托福TPO24综合写作阅读原文+听力原文+满分范文

Tpo24Lake WaterWhere does the water in a lake come from, and how does water leave it? Water enters a lake from inflowing rivers, from underwater seeps and springs, from overland flow off the surrounding land, and from rain falling directly on the lake surface. Water leaves a lake via outflowing rivers, by soaking into the bed of the lake, and by evaporation. So much is obvious.The questions become more complicated when actual volumes of water are considered: how much water enters and leaves by each route? Discovering the inputs and outputs of rivers is a matter of measuring the discharges of every inflowing and outflowing stream and river. Then exchanges with the atmosphere are calculated by finding the difference between the gains from rain, as measured (rather roughly) by rain gauges, and the losses by evaporation, measured with models that correct for the other sources of water loss. For the majority of lakes, certainly those surrounded by forests, input from overland flow is too small to have a noticeable effect. Changes in lake level not explained by river flows plus exchanges with the atmosphere must be due to the net difference between what seeps into the lake from the groundwater and what leaks into the groundwater. Note the word "net": measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference.Once all this information has been gathered, it becomes possible to judge whether a lake’s flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. Occasionally, common sense tells you which of these two possibilities applies. For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated.By whatever means, a lake is constantly gaining water and losing water: its water does not just sit there, or, anyway, not for long. This raises the matter of a lake’s residence time. The residence time is the average length of time that any particular molecule of water remains in the lake, and it is calculated by dividing the volume of water in the lake by the rate at which water leaves the lake. The residence time is an average; the time spent inthe lake by a given molecule (if we could follow its fate) would depend on the route it took: it might flow through as part of the fastest, most direct current, or it might circle in a backwater for an indefinitely long time.Residence times vary enormously. They range from a few days for small lakes up to several hundred years for large ones; Lake Tahoe, in California, has a residence time of 700 years. The residence times for the Great Lakes of North America, namely, Lakes Superior, Michigan, Huron, Erie, and Ontario, are, respectively, 190,100,22,2.5, and 6 years. Lake Erie’s is the lowest: although its area is larger than Lake Ontario’ s, its volume is less than one-third as great because it is so shallow-less than 20 meters on average.A given lake’s residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporation rate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario, Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (the rate at which water is lost to the atmosphere through evaporation and the processes of plant life).The result has been that the residence time of one of the lakes increased from 5 to 18 years during the study period. The slowing down of water renewal leads to a chain of further consequences; it causes dissolved chemicals to become increasingly concentrated, and this, in turn, has a marked effect on all living things in the lake.paragraph1: Where does the water in a lake come from, and how does water leave it? Water enters a lake from inflowing rivers, from underwater seeps and springs, from overland flow off the surrounding land, and from rain falling directly on the lake surface. Water leaves a lake via outflowing rivers, by soaking into the bed of the lake, and by evaporation. So much is obvious.1. The phrase So much in the passage refers to○the negative effects of overland flow, rain, and evaporation on river water levels○water that a lake loses to outflowing rivers, to the lake bed, and to evaporation○the importance of rivers to the maintenance of lake water levels○the information given about ways that water can enter or exit a lakeparagraph2: The questions become more complicated when actual volumes of water are considered: how much water enters and leaves by each route? Discovering the inputs and outputs of rivers is a matter of measuring the discharges of every inflowing and outflowing stream and river. Then exchanges with theatmosphere are calculated by finding the difference between the gains from rain, as measured (rather roughly) by rain gauges, and the losses by evaporation, measured with models that correct for the other sources of water loss. For the majority of lakes, certainly those surrounded by forests, input from overland flow is too small to have a noticeable effect. Changes in lake level not explained by river flows plus exchanges with the atmosphere must be due to the net difference between what seeps into the lake from the groundwater and what leaks into the groundwater. Note the word "net": measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference.2. The word in the passage is closest in meaning to○results○increases○resources○savings3. Which of the following can be inferred from paragraph 2 about the movement of water into a lake?○Heavy rain accounts for most of the water that enters into lakes.○Rainfall replaces approximately the amount of water lost through evaporation.○Overland flow into lakes is reduced by the presence of forests.○Seepage has a smaller effect on water level than an y other input.4. Why does the author use the phrase Note the word "net" in the passage?○To emphasize the impact of seepage on water levels○To point out that seepage is calculated differently from river flows and atmospheric exchanges○To compare the different methods of calculating seepage○To emphasize the difficulty of obtaining specific values for seepage inputs and outputsparagraph3: Once all this information has been gathered, it becomes possible to judge whether a lake’s flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. Occasionally, common sense tells you which of these two possibilities applies. For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated.5. The word Conversely meaning to○on the other hand○in the same way○in other words○on average6. According to paragraph 3, which of the following best describes a seepage-dominated lake?○A lake that is fed by streams but still has fluctuating water levels○A lake with a constant water level that has no streams or rivers as inputs○A lake with a stream flowing into it and a stream flowing out of i t○A lake that has surface and underground inputs but loses water during dry seasonsparagraph4: By whatever means, a lake is constantly gaining water and losing water: its water does not just sit there, or, anyway, not for long. This raises the matter of a lake’s residence time. The residence time is the average length of time that any particular molecule of water remains in the lake, and it is calculated by dividing the volume of water in the lake by the rate at which water leaves the lake. The residence time is an average; the time spent in the lake by a given molecule (if we could follow its fate) would depend on the route it took: it might flow through as part of the fastest, most direct current, or it might circle in a backwater for an indefinitely long time.7. It can be inferred from paragraph 4 that the length of time a given molecule of water remains in a lake○depends entirely upon the average speed of a lake' s currents○can be measured b y the volume of the lake alone○can be greater or lesser than the residence time○is similar to the length of time all other molecules remain in that lakeparagraph5: Residence times vary enormously. They range from a few days for small lakes up to several hundred years for large ones; Lake Tahoe, in California, has a residence time of 700 years. The residence times for the Great Lakes of North America, namely, Lakes Superior, Michigan, Huron, Erie, and Ontario, are, respectively, 190,100,22,2.5, and 6 year s. Lake Erie’s is the lowest: although its area is larger than Lake Ontario’ s, its volume is less than one-third as great because it is so shallow-less than 20 meters on average.8. According to paragraph 5, Lake Erie's residence time is lower than Lake Ontario's for which of the followingreasons?○Lake Erie has a larger area than Lake Ontario.○Lake Ontario is shallower than Lake Erie.○Lake Ontario has a greater volume than Lake Erie.○Lake Erie receives less rainfall than Lake Ontario.9. Why does the author discuss the Great Lakes in paragraph 5?○To demonstrate the extent to which residence times vary from lake to lake○To illustrate how residence times are calculated for specific lakes○To argue that the residence time of a lake increases with area○To emphasize that Lake Tahoe' s residence time is unusually longParagraph 6: A given lake's residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporation rate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario. Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (therate at which water is lost to the atmosphere through evaporation and the processes of plant life). Thechemicals to become increasingly concentrated, and this, in turn, has a marked effect on all living things in the lake.○expected○additional○serious○unfortunate11. According to paragraph 6, which of the following explains the increase in residence time of some lakes of northwestern Ontario?○The amount of water flowing into the lakes has increased.○The rate of evaporation has decreased more sharply than the amount of rainfall.○The renewal of the lakes' water has slowed due to changes in climate.○Plants have required less water from the lakes12. According to paragraph 6, residence time is affected by all of the following EXCEPT○amount of rainfall○rate of evaporation ○temperature of surrounding air○concentration of chemicals in lake waterparagraph3: Once all this information has been gathered, it becomes possible to judge whether a lake’s flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. [■] If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. [■] Occasionally, common sense tells you which of these two possibilities applies. [■] For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one endand out the other, which dries up when the stream dries up, is clearly surface water dominated. [■]13. Look at the four squares III that indicate where the following sentence could be added to the passage.Of course, a lake may be neither surface-water-nor seepage-dominated if, for example, its inputs are predominantly surface and its outputs are predominantly seepage.Where would the sentence best fit? Click on a square to add the sentence to the passage.14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage.This question is worth 2 points.Water enters, remains, and eventually leaves a lake in a variety of ways.●●●Answer Choices○By measuring the water quantities at each of a lake's inputs and outputs, it can be determined whether water enters the lake mainly from surface or groundwater sources.○Changes in lake level and volume are caused principally by the amount of evaporat ion of water into the atmosphere.○It is sometimes possible to decide whether a lake is surface water dominated or seepage ○dominated by simple observation at different seasons.○The average period of time that molecules of water spend in a lake—the residence time—varies from lake to lake and overtime within a particular lake.○The residence times of surface-water-dominated lakes are usually longer than those of seepage-dominated lakes.○The residence time of a lake frequently depends on the kinds of organis ms to be found in the lake.参考答案:1.42.23.34.45.16.27.38.39.110. 211. 312. 413. 414.By measuring the...It is sometimes possible to decide...The average period of time。

托福阅读TPO24(试题+答案+译文)第2篇:BreathingDuringSleep整理为了关心大家备考托福阅读，提高成果，下面我给大家带来托福阅读TPO24(试题+答案+译文)第2篇:Breathing During Sleep，盼望大家喜爱!托福阅读原文【1】Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. However, there are many other changes that affect respiration when asleep.【2】During wakefulness, breathing is controlled by two interacting systems. The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.【3】During NREM (the phase of sleep in which there is no rapid eye movement) breathing becomes deeper and more regular, but there is also a decrease in the breathing rate, resulting in less air being exchanged overall. This occurs because during NREM sleep the automatic, metabolic system has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide. Also, during sleep the automatic metabolic system is less responsive to carbon dioxide levels and oxygen levels in the blood. Two things result from these changes in breathing control that occur during sleep. First, there may be a brief cessation or reduction of breathing when falling asleep as the sleeper waxes and wanes between sleep and wakefulness and their differing control mechanisms. Second, once sleep is fully obtained, there is an increase of carbon dioxide and a decrease of oxygen in the blood that persists during NREM.【4】But that is not all that changes. During all phases of sleep, several changes in the air passages have been observed. It takes twice as much effort to breathe during sleep because of greater resistance to airflow in the airways and changes in the efficiency of the muscles used for breathing. Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep, especially during REM (the phase of sleep in which there is rapid eye movement). Without this muscular action, inhaling is like sucking air out of a balloon—the narrow passages tend to collapse. Also there is a regular cycle of change in resistance between the two sides of the nose. If something blocks the good side, such as congestion from allergies or a cold, then resistance increases dramatically. Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.【5】Other respiratory regulating mechanisms apparently ceasefunctioning during sleep. For example, during wakefulness there is an immediate, automatic, adaptive increase in breathing effort when inhaling is made more difficult (such as breathing through a restrictive face mask). This reflexive adjustment is totally absent during NREM sleep. Only after several inadequate breaths under such conditions, resulting in the considerable elevation of carbon dioxide and reduction of oxygen in the blood, is breathing effort adjusted. Finally, the coughing reflex in reaction to irritants in the airway produces not a cough during sleep but a cessation of breathing. If the irritation is severe enough, a sleeping person will arouse, clear the airway, then resume breathing and likely return to sleep.【6】Additional breathing changes occur during REM sleep that are even more dramatic than the changes that occur during NREM. The amount of air exchanged is even lower in REM than NREM because, although breathing is more rapid in REM,it is also more irregular, with brief episodes of shallow breathing or absence of breathing. In addition, breathing during REM depends much more on the action of the diaphragm and much less on rib cage action.托福阅读试题1.According to paragraph 1, which of the following can be inferred about the diaphragm during sleep?A.During sleep the diaphragm requires increased movement of the rib cage.B.The diaphragm helps with breathing as movements of the rib cage decrease during sleep.C.The diaphragm requires a great amount of pressure to function properly.D.The diaphragm contributes to the effective functioning of the rib cage.2.According to paragraph 2, all of the following are true of the voluntary breathing system EXCEPT:A.It has its control center in the brain stem.B.It controls breathing for a number of activities during wakefulness.C.It is able to bypass the automatic system.D.It produces an irregular breathing pattern.3.The word exclusive in the passage (paragraph 3) is closest in meaning toA.consistentB.perfectC.partialD.sole4.According to paragraph 3, which of the following may occur just before NREM sleep begins?A.The automatic, metabolic system may increase its dependence on air exchanges.B.Breathing can stop for a short time as a person falls asleep.C.An increase in the oxygen level in the blood can occur as sleep becomes fully obtained.D.The level of carbon dioxide in the blood may drop suddenly.5.What is the authors purpose in stating that inhaling is like sucking air out of a balloon?(in paragraph 4)A.To refute the argument that additional effort is necessary for breathing during sleep.B.To argue that REM sleep is more important than NREM sleep.C.To illustrate the difficulty of breathing during sleep.D.To illustrate how blockage of narrow passages can be prevented during sleep.6.All of the following are mentioned in paragraph 4 as being characteristic of breathing during sleep EXCEPTA.relaxation of the muscles involved in the respiratory system.B.changes in resistance between the two sides of the nose.C.easier airflow in the passages of the upper airway.D.absence of certain complex muscle interactions.7.According to paragraph 5, what happens during NREM sleep when inhaling is difficult?A.There is an immediate, automatic, adaptive increase in breathing effort.B.The sleeping person takes several inadequate breaths before the breathing effort is adjusted.C.The coughing reflex causes the breathing effort to adjust.D.The airways become cleared as the blood removes irritants.8.It can be inferred from paragraph 5 that a very mild irritation during sleep will likely cause the sleeping person toA.increase the breathing effort.B.wake up and remove the source of irritation.C.cough while still sleeping.D.stop breathing temporarily while still sleeping.9.The word considerable (paragraph 5)meaning toA.significant.B.Steady.ual.D.necessary.10.The word resume in the passage (paragraph 5) is closest in meaning toA.reduce.B.stop.C.readjust.D.restart.11.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage (paragraph 6)? Incorrect choices change the meaning in important ways or leave out essential information.A.Because breathing is more shallow and irregular in REM than in NREM, less air is exchanged in REM.B.Breathing in NREM is less effective than breathing in REM because of irregular episodes of rapid breathing during NREM.C.Because breathing is more rapid in NREM sleep than in REM sleep, breathing often becomes shallow.D.Although REM has brief episodes of shallow breathing or lack of breathing, breathing is more rapid than in NREM.12. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? Click on a square to add the sentence to the passage. To better understand breathing during sleep, it is, however, helpful to first understand how respiration works in general.paragraph1: Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. [■]【A】Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. [■]【B】However, there are many other changes that affect respiration when asleep.paragraph2: [■]【C】During wakefulness, breathing is controlled by two interacting systems. [■]【D】The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.13.Directions: From the seven statements below, select the statements that correctly characterize breathing during wakefulness and those statements that correctly characterize breathing during sleep. Drag each answer choice you select into the appropriate box of the table. Two of the answer choices will NOT be used. This question is worth 3 points.A.The role of the rib cage increases and the role of the diaphragm decreases.B.Carbon dioxide in blood rises and oxygen drops.C.The coughing reflex is extremely complex.D.A great deal of effort is used for breathing.E.Upper airways are resistant to colds and allergies.F.There is a drop in the volume of air that is exchanged.G.Automatic and voluntary respiratory systems are both involved.1 )WakefulneA B C D E F G2 )SleepA B C D E F G托福（阅读答案）1.以diaphragm做关键词定位至第三句和第四句，说ribcage运动变少，使得diaphragm更重要，但stomach的压力使得diaphragm工作起来更困难，B是正确答案。

托福考试 复习托福阅读TPO24(试题+答案+译文)第3篇:Moving into Pueblos托福阅读原文【1】In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.【2】Given all the disadvantages of living in aggregated towns, why did people in the thirteenth century move into these closely packed quarters?For transitions of such suddenness, archaeologists consider either pull factors (benefits that drew families together) or push factors (some external threat or crisis that forced people to aggregate). In this case, push explanations dominate.【3】Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos.Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields. 【4】Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the SanJuan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.【5】In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenthcentury. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.托福阅读试题1.The word traumatic(paragraph 1)meaning toA.Essential.B.highly stressful.C.highly unusual.D.unwise.2.The word intense in the passage(paragraph 1)is closest in meaningtoA.strong.B.questionable.C.obvious.D.deliberate.3.According to paragraph 1, before the thirteenth century the people of southwestern North America lived in households thatA.shared daily chores with neighboring households.B.occupied dwellings that were built into the sides of cliffs.C.were largely free to conduct their lives as they pleased.D.enforced common standards of behavior and cooperative conduct within their communities.4.Which of the following best indicates the organization of paragraph 1?A.It presents the conditions that caused a change in a population' s living patterns and then explains why those conditions got worse.B.It identifies certain present-day cultural traditions and rules and then traces them to their roots in the thirteenth century.C.It casts doubt on one explanation of the move to pueblos and then introduces an alternative explanation that the passage will defend.D.It describes a major change in a population' s living patterns and then presents a number of problems that resulted from that change.5.According to paragraph 3, which of the following was one of the consequences of increasing population densities?A.People were increasingly crowded into collections of large housing units.B.People stopped planting crops that have relatively low yields.C.Domestic buildings were pushed beyond the canyon limits.D.The natural landscape was destroyed.6.Which of the sentences below best expresses the essential information inthe highlighted sentence in the passage(paragraph 4)?Incorrect choiceschange the meaning inimportant ways or leave out essential information.A.Some scholars even claim that the intensification of farmers' various efforts during the 1200s led to further population growth and the consequent need for more arable land.B.Evidence of intensifying agriculture in the 1200s indicates a need to feed a larger population and so extends the argument that a growing population was the cause of the move to pueblos.C.During the 1200s, farmers met the demand for more arable land, but they also succeeded in cultivating existing land more intensively with the help of agricultural construction projects.D.Some scholars feel strongly that the construction of small dams, reservoirs, terraces, and field houses in the thirteenth century is independent evidence for growth in the number of people.7.The word transition(paragraph 4)in the passage is closest in meaning toA.change.B.climate.C.decline.D.problem.8.Why does the author state that "Growing food at these elevations is always difficult because of the short growing season"?A.To explain why the higher elevations were always relatively sparselypopulated.B.To suggest that any worsening of conditions would have significant consequences.C.To emphasize how resourceful the people growing food at these elevations were.D.To argue that farming was not the primary source of food at high elevations.9.According to paragraph 4, what did farmers do in response to falling temperatures during the Little Ice Age?A.Moved to areas away from Mesa Verde.B.Moved closer to the northeastern part of Mesa Verde.C.Began to cultivate crops adapted to a short growing season.D.Gave up the cultivation of the highest-lying lands.10.According to paragraph 5, major ceremonial events were occasions forA.leaders to persuade people from the countryside to move into a pueblo.B.farmers to collect information about where crops could be reliably grown.C.people to develop better techniques for producing pottery and crafts.D.people in the early Puebloan era to share farm and craft products.11.According to paragraph 5, which of the following was a reason people in the Mesa Verde area formed communal villages in the thirteenth century?A.The climate in the Mesa Verde area became more locally diverse.B.Individuals were no longer interested in exchanging pottery and food.C.Cooperation between people became more important for survival.D.Bad years of farming began to occur more frequently.12.Paragraph 5 supports which of the following statements about cooperation among the people in the Mesa Verde area from the eleventh through the thirteenth century?A.Cooperation allowed many households to give up farming and to specialize in making pottery and crafts.B.People went from exchanging food and crafts they individually produced to sharing in a cooperative effort to produce as much food as possible.C.Overtime there was less cooperation as farmers competed with each other for trade with distant areas.D.Individuals stopped cooperating with each other because they did not have enough food for themselves.13. Look at the four squares [■] that indicate where the following sentence could be added to the passage.Where would the sentence best fit? Click on a square to add the sentence to the passage. Performing everyday household tasks required more effort.In the Mesa Verde area of the ancient North American Southwest, livingpatterns changed in the thirteenth century, with large numbers ofpeople movinginto large communal dwellings called pueblos, often constructed at the edges ofcanyons, especially on the sides of cliffs. Abandoning small extended-familyhouseholds to move into these large pueblos with dozens if not hundreds ofother people was probably traumatic. Few of the cultural traditions and rulesthat today allow us to deal with dense populations existed for these peopleaccustomed to household autonomy and the ability to move around the landscapealmost at will. ■【A】And besides theawkwardness of having to share walls with neighbors, living in aggregatedpueblos introduced other problems. ■【B】For people in cliff dwellings, hauling water, wood,and food to their homes was a major chore. ■【C】The stress on local resources, especially in thefirewood needed for daily cooking and warmth, was particularly intense, andconditions in aggregated pueblos were not very hygienic. ■]【D】14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage.This question is worth 2 points.In the thirteenth century, the people in the Mesa Verdearea went from living in scattered independent households to living in largepueblos.A.Because the thirteenth-century inhabitants of the Mesa Verde area did not have the cultural expectations of today's city dwellers, they easily adapted to communal life.B.Even though living in pueblos had disadvantages, the population of the area had grown so large that there may have been no other arrangement that would have met its needs.C.From the eleventh century onward, farmers began to increase food production on existing farmland and started bringing more land under cultivation.D.A development that contributed to increasing population densities was a cooling climate that led many people to leave the coldest areas and crowd into climatically more favorable areas.E.The primary reason for moving to pueblos was the social benefits associated with communal life.F.People were brought together by the need to produce food cooperatively, as the use of food surpluses in one place to relieve shortages in another ended due to a change in climate.托福阅读答案1.traumatic受伤的，外伤的，不顺心的，所以正确答案是highly stressful。

为了帮助大家高效备考托福，为大家带来托福TPO24口语Task6听力文本+题目+满分范文，希望对大家备考有所帮助。

托福TPO24口语Task6听力文本： Listen to part of a lecture in a literature class. (female professor) Authors of fiction, um, short stories and novels, of course have many decisions to make when they're writing their works. One of those decisions is how they are going to narrate or tell the story. What perspective or what point of view the story would be told from? So, authors need to choose a type of narrator, some person or voice to tell the story. And this narrator can affect the readers' experience when they read the story.Now, the author might choose to have an objective narrator. An objective narrator can describe what people, the characters in the story, what they do and what they say, but that's about all. So, suppose we have a story, for example, that is about a man and woman about to take a trip. When the story is told by an objective narrator, the only information that we get as readers is what the characters say to each other, what they do. They get on the train, they sit down, they look out the window, that’s all. And this leaves questions that force the reader to interpret the events, to fill in information and decide what the characters’ conversation and actions might mean. Another kind of narrator an author might use is an omniscient narrator. In this case, the narrator, the voice that is telling the story, knows everything, and I mean everything about the characters. So, let’s imagine our same man and woman traveling but described by an omniscient narrator. Not only do we, the readers, know what they do and say, but we also know what they’re thinking. For example, we’re told that the couple is going to visit an old friend of the man ’s and we learn what the man is thinking that he is nervous because he hasn’t seen his friend in a long time, that he is worried if his wife would like the friend. So an omniscient narrator provides more information and answers questions that the reader might have about the characters or the action. 托福TPO24口语Task6题目： Using the examples from the lecture, discuss two types of narrators that an author of fiction might use. 托福TPO24口语Task6满分范文： There're two types of narrator/perspectives of storytelling. The first one is objective narrator, by which the writer only shows what the characters say and what they do, and leaves the rest to the readers to imagine and fill in the information. For example, there's story in which a man and a woman are about to take a trip, and we only know that they get on the train and look out the window, but we have no idea what they're thinking. Objective narrator doesn't provide the information. But byomniscient narrator, the readers can know everything about the characters, including what they're thinking and why they do the things they do. Back to the train story, by omniscient narrator, we probably will not only know that they're on a trip, but also know that they go on the trip to visit one of the man's old friends, and the man is worrying about what to say to his friend since they haven't seen each other for a while and whether his wife would like his friend. (185 words) 以上是给大家整理的托福TPO24口语Task6听力文本+题目+满分范文，希望对你有所帮助!。

托福考试 复习托福阅读TPO24(试题+答案+译文)第1篇:Lake Water托福阅读原文【1】Where does the water in a lake come from, and how does water leave it? Water enters a lake from inflowing rivers, from underwater seeps and springs, from overland flow off the surrounding land, and from rain falling directly on the lake surface. Water leaves a lake via outflowing rivers, by soaking into the bed of the lake, and by evaporation. So much is obvious.【2】The questions become more complicated when actual volumes of water are considered: how much water enters and leaves by each route? Discovering the inputs and outputs of rivers is a matter of measuring the discharges of every inflowing and outflowing stream and river. Then exchanges with the atmosphere are calculated by finding the difference between the gains from rain, as measured (rather roughly) by rain gauges, and the losses by evaporation, measured with models that correct for the other sources of water loss. For the majority of lakes, certainly those surrounded by forests, input from overland flow is too small to have a noticeable effect. Changes in lake level not explained by river flows plus exchanges with the atmosphere must be due to the net difference between what seeps into the lake from the groundwater and what leaksinto the groundwater. Note the word "net": measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference. 【3】Once all this information has been gathered, it becomes possible to judge whether a lake’s flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. Occasionally, common sense tells you which of these two possibilities applies. For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated.【4】By whatever means, a lake is constantly gaining water and losing water: its water does not just sit there, or, anyway, not for long. This raises the matter of a lake’s residence time. The residence time is the average length of time that any particular molecule of water remains in the lake, and it is calculated by dividing the volume of water in the lake by the rate at which water leaves the lake. The residence time is an average; the time spent in the lake by a given molecule (if we could follow its fate) would depend on the route it took: it might flow through as part of the fastest,most direct current, or it might circle in a backwater for an indefinitely long time.【5】Residence times vary enormously. They range from a few days for small lakes up to several hundred years for large ones; Lake Tahoe, in California, has a residence time of 700 years. The residence times for the Great Lakes of North America, namely, Lakes Superior, Michigan, Huron, Erie, and Ontario, are, respectively, 190,100,22,2.5, and 6 years. Lake Erie’s is the lowest: although its area is larger than Lake Ontario’ s, its volume is less than one-third as great because it is so shallow-less than 20 meters on average.【6】A given lake’s residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporation rate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario, Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (the rate at which water is lost to the atmosphere through evaporation and the processes of plant life).【7】The result has been that the residence time of one of the lakes increased from 5 to 18 years during the study period. The slowing down of water renewal leads to a chain of further consequences; it causesdissolved chemicals to become increasingly concentrated, and this, in turn, has a marked effect on all living things in the lake.托福阅读试题1.The phrase So much in the passage (paragraph 1) refers toA.the negative effects of overland flow, rain, and evaporation on river water levels.B.water that a lake loses to outflowing rivers, to the lake bed, and to evaporation.C.the importance of rivers to the maintenance of lake water levels.D.the information given about ways that water can enter or exit a lake.2.The word gains in the passage (paragraph 2) is closest in meaning toA.results.B.increases.C.resources.D.savings.3.Which of the following can be inferred from paragraph 2 about the movement of water into a lake?A.Heavy rain accounts for most of the water that enters into lakes.B.Rainfall replaces approximately the amount of water lost through evaporation.C.Overland flow into lakes is reduced by the presence of forests.D.Seepage has a smaller effect on water level than any other input.4.Why does the author use the phrase Note the word "net" in the passage (paragraph 2)?A.To emphasize the impact of seepage on water levels.B.To point out that seepage is calculated differently from river flows and atmospheric exchanges.C.To compare the different methods of calculating seepage.D.To emphasize the difficulty of obtaining specific values for seepage inputs and outputs.5.The word Conversely in paragraph 3 meaning toA.on the other hand.B.in the same way.C.in other words.D.on average.6.According to paragraph 3, which of the following best describes a seepage-dominated lake?A.A lake that is fed by streams but still has fluctuating water levels.B.A lake with a constant water level that has no streams or rivers as inputs.C.A lake with a stream flowing into it and a stream flowing out of it.D.A lake that has surface and underground inputs but loses water during dry seasons.7.It can be inferred from paragraph 4 that the length of time a given molecule of water remains in a lakeA.depends entirely upon the average speed of a lake' s currents.B.can be measured by the volume of the lake alone.C.can be greater or lesser than the residence time.D.is similar to the length of time all other molecules remain in that lake.8.According to paragraph 5, Lake Erie's residence time is lower than Lake Ontario's for which of the following reasons?ke Erie has a larger area than Lake Ontario.ke Ontario is shallower than Lake Erie.ke Ontario has a greater volume than Lake Erie.ke Erie receives less rainfall than Lake Ontario.9.Why does the author discuss the Great Lakes in paragraph 5?A.To demonstrate the extent to which residence times vary from lake to lake.B.To illustrate how residence times are calculated for specific lakes.C.To argue that the residence time of a lake increases with area.D.To emphasize that Lake Tahoe' s residence time is unusually long.10.The word further in the passage (paragrapg 6)is closest in meaning toA.expected.B.additional.C.serious.D.unfortunate.11.According to paragraph 6, which of the following explains the increase in residence time of some lakes of northwestern Ontario?A.The amount of water flowing into the lakes has increased.B.The rate of evaporation has decreased more sharply than the amount of rainfall.C.The renewal of the lakes' water has slowed due to changes in climate.D.Plants have required less water from the lakes.12.According to paragraph 6, residence time is affected by all of the following EXCEPTA.amount of rainfall.B.rate of evaporation.C.temperature of surrounding air.D.concentration of chemicals in lake water.13. Look at the four squares III that indicate where the following sentence could be added to the passage. Where would the sentence best fit? Click on a square to add the sentence to the passage. Of course, a lake may be neither surface-water-nor seepage-dominated if, for example, its inputs are predominantly surface and its outputs are predominantly seepage. paragraph3: Once all this information has been gathered, it becomes possible to judge whether a lake’s flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. [■]【A】If theformer are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. [■]【B】Occasionally, common sense tells you which of these two possibilities applies. [■]【C】For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated. [■]【D】14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Water enters, remains, and eventually leaves a lake in a variety of ways.A.By measuring the water quantities at each of a lake's inputs and outputs, it can be determined whether water enters the lake mainly from surface or groundwater sources.B.Changes in lake level and volume are caused principally by the amount of evaporation of water into the atmosphere.C.It is sometimes possible to decide whether a lake is surface water dominated or seepage dominated by simple observation at differentseasons.D.The average period of time that molecules of water spend in a lake—the residence time—varies from lake to lake and overtime within a particular lake.E.The residence times of surface-water-dominated lakes are usually longer than those of seepage-dominated lakes.F.The residence time of a lake frequently depends on the kinds of organisms to be found in the lake.托福阅读答案1.So much指代前文，说water是怎么enter怎么leave的，所以正确答案是D。

¡¡¡¡ÎªÁË°ïÖú´ó¼Ò¸ßЧ±¸¿¼Íи££¬Îª´ó¼Ò´øÀ´Íи£TPO24ÔĶÁPassage2Ô-ÎÄÎı¾+ÌâÄ¿+´ð°¸½âÎö£¬Ï£Íû¶Ô´ó¼Ò±¸¿¼ÓÐËù°ïÖú¡£¡¡¡¡¨ Íи£TPO24ÔĶÁPassage2Ô-ÎÄÎı¾£º¡¡¡¡Breathing During Sleep¡¡¡¡Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade,changes in respiratory control are most dramatic.Not only are there differences in the level of the functioning of respiratory systems,there are even changes in how they function.Movements of the rib cage for breathing are reduced during sleep,making the contractions of the diaphragm more important.Yet because of the physics of lying down,the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job.However,there are many other changes that affect respiration when asleep.¡¡¡¡During wakefulness,breathing is controlled by two interacting systems.The first is an automatic,metabolic system whose control is centered in the brain stem.It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide(CO2)and oxygen(O2),and the acid-base ratio in the blood.The second system is the voluntary,behavioral system.Its control center is based in the forebrain,and it regulates breathing for use in speech,singing,sighing,and so on.It is capable of ignoring or overriding the automatic,metabolic system and produces an irregular pattern of breathing.¡¡¡¡During NREM(the phase of sleep in which there is no rapid eye movement)breathing becomes deeper and more regular,but there is also a decrease in the breathing rate,resulting in less air being exchanged overall.This occurs because during NREM sleep the automatic,metabolic system has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide.Also,during sleep the automatic metabolic system is less responsive to carbon dioxide levels and oxygen levels in the blood.Two things result from these changes in breathing control that occur during sleep.First,there may be a brief cessation or reduction of breathing when falling asleep as the sleeper waxes and wanes between sleep and wakefulness and their differing control mechanisms.Second,once sleep is fully obtained,there is an increase of carbon dioxide and a decrease of oxygen in the blood that persists during NREM.¡¡¡¡But that is not all that changes.During all phases of sleep,several changes in the air passages have been observed.It takes twice as much effort to breathe during sleep because of greater resistance to airflow in the airways and changes in the efficiency of the muscles used for breathing.Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep,especially during REM(the phase of sleep in which there is rapid eye movement).Without this muscular action,inhaling is like sucking air out of a balloon¡ªthe narrow passagestend to collapse.Also there is a regular cycle of change in resistance between the two sides of the nose.If something blocks the"good"side,such as congestion from allergies or a cold,then resistance increases dramatically.Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.¡¡¡¡Other respiratory regulating mechanisms apparently cease functioning during sleep.For example,during wakefulness there is an immediate,automatic,adaptive increase in breathing effort when inhaling is made more difficult(such as breathing through a restrictive face mask).This reflexive adjustment is totally absent during NREM sleep.Only after several inadequate breaths under such conditions,resulting in the considerable elevation of carbon dioxide and reduction of oxygen in the blood,is breathing effort adjusted.Finally,the coughing reflex in reaction to irritants in the airway produces not a cough during sleep but a cessation of breathing.If the irritation is severe enough,a sleeping person will arouse,clear the airway,then resume breathing and likely return to sleep.¡¡¡¡Additional breathing changes occur during REM sleep that are even more dramatic than the changes that occur during NREM.The amount of air exchanged is even lower in REM than NREM because,although breathing is more rapid in REM,it is also more irregular,with brief episodes of shallow breathing or absence of breathing.In addition,breathing during REM depends much more on the action of the diaphragm and much less on rib cage action.¡¡¡¡paragraph1:Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade,changes in respiratory control are most dramatic.Not only are there differences in the level of the functioning of respiratory systems,there are even changes in how they function.Movements of the rib cage for breathing are reduced during sleep,making the contractions of the diaphragm more important.Yet because of the physics of lying down,the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job.However,there are many other changes that affect respiration when asleep.¡¡¡¡¨ Íи£TPO24ÔĶÁPassage2ÌâÄ¿£º¡¡¡¡1.According to paragraph 1,which of the following can be inferred about the diaphragm during sleep?¡¡¡¡¡ðDuring sleep the diaphragm requires increased movement of the rib cage.¡¡¡¡¡ðThe diaphragm helps with breathing as movements of the rib cage decrease during sleep.。

托福听力TPO24原文Lecture4下面就让小编来为大家介绍一下托福听力TPO24原文中Lecture4的文本内容吧，大家要好好把握，这些都是非常有价值的材料，同时，大家也可以登录前程百利论坛进行TPO练习辅导，希望能够给准备托福听力的同学带来帮助。

TPO24Lecture4-Astronomy(Shield Volcanoes on Venus)Professor：Many people have been fascinated about Venus for centuries because of its thick cloud cover,this so-called planet of mystery and all of that.Well,what's under those clouds?What's the surface of the planet like?Some questions about the surface are still unresolved but,but we have learned a lot about it in the past several years.First of all,let me talk about how we have been able to get past those clouds.First,there were Soviet modules2that landed directly on the surface and sent back some images ofwhat was around them.Second,we did some radar imaging from satellites from above.Radar can get through the clouds.So what have we learned?Yes,Karen?Student：Well,I remember reading that there's not really a lot going on,that the surface of Venus is just flat and smooth in a lot of places.Professor：Yeah,smooth in a lot of places.But that's not,um...that's not the whole picture.In other areas,you've got canyons,ripped valleys,meteo craters,uh,lava domes, these lava formations that look like giant pancakes.And also volcanoes.Well,one of the most interesting features on the surface are in fact the shield volcanoes.Shield volcanoes formed when magma comes out of the ground in the same spot over and over again.Remember, magma is hot molten rock that's underground,and it is called lava when it reaches the surface. Uh,so the lava builds up,and hardens,and a volcano forms.Now,the lava on Venus is thin. It spreads out easily.So shield volcanoes have very gentle sloping sides.They are called shield volcanoes,because viewed from above,they kind of resemble shields,you know,like a warrior's shield.But what's particularly interesting about these volcanoes is that most of the volcanoes here on Earth are not shield volcanoes.Instead,they are other volcano types,like strata volcanoes,for example,which are a result of tectonic plate movement. Remember tectonic plates?Underneath the Earth's crust,there are a number of shifting slabs or plates that are slowly moving.And in the zones on the edges of the plates where differentplates meet and interact,that's where we get most of Earth's volcanoesOn Venus,however, volcanoes are not clustered in discrete zones like they are on Earth.Instead,they are more or less randomly scattered over Venus's surface.Well,that's significant.Venus has mostly shield volcanoes,and they are randomly scattered,that indicates that Venus does not have moving tectonic plates,and that's a big difference compared to Earth.Here on Earth,moving tectonic plates are a major geological element,just crucial for the whole surface dynamic,right?So why doesn't Venus have them?Well,there are a few theories.One of them is that this has to do with the fact that Venus has no surface water that's needed to kind of lubricate the movement of the plates,you know,like oceans on Earth.Yeah,I forgot to spell that out.Uh,Venus has no surface water.Student：Wait a second.Did you say we have shield volcanoes on Earth?Can you give an example?Professor：Sure.The volcanoes in the Hawaii islands,in the Pacific Ocean are shield volcanoes.They are formed over a hot spot of magma.So while on Earth we have several types of volcanoes,on Venus there's mostly the one type.Uh,Eric?Student：Are the volcanoes on Venus still active?Professor：Well,that's an interesting question.There is still some discussion on that point.But here's what we do now.First,the level of sulfur dioxide gas above Venus's clouds shows large and very frequent fluctuations.It is quite possible that these fluctuations, the huge increase and decrease of sulfur dioxide,happening again and again.It's quite possible that this is due to volcanic eruptions,because volcanic eruptions often emit gases. If that's the case,volcanism could very well be the root cause of Venus's thick cloud cover. And also we have observed bursts of radio energy from the planet's surface.These bursts are similar to what we see when volcanoes erupt on Earth.So this too suggests ongoing volcanic activity.But although this is intriguing evidence,no one's actually observed a Venus volcano erupting yet,so we can't be positive.教授：几个世纪来许多人都对厚云层覆盖的金星有着深厚的兴趣，它被称之为神秘的星球。

托福TPO24综合写作阅读+听力原文+满分范文【雷哥托福整理】考过的同学会发现托福综合作文分数不高，很大程度上是受我们听力实力的影响，我们很多托福考生的听力分数只有16分上下的时候，对于托福综合作文的听力妥妥的是束手无策，而且很多托福考生还感觉自己都听懂了，那也只能说明你听懂了大意，但是听力里面要的是每一个细节！请注意，是每一个细节！雷哥托福小托君给大家分享TPO1-33综合作文部分的阅读和听力文本全集与综合作文的满分作文，以及满分作文的解析。

如果自己的托福综合作文分数如果可以很给力的话，就已经搞定了15分的分数，可以极大地缓解托福独立作文的压力。

如何使用这个文件呢？做托福TPO模考之后，可以根据这里面的听力的文本，来检验自己的听力内容是否抓的足够好，尤其是要看写的够不够全！在托福考试前来做跟读，口语实力不够，那么做跟读，仔细地来模仿ETS官方素材，是一个很好的提高自己口语的方式。

熟悉托福考试的专业词汇。

不少托福考生之所以在听力考试里面不够给力，是因为对于里面的专业词汇不够熟悉。

毕竟在托福考试过程中，如果核心词汇都不懂的话，那么在听力部分只能是束手就擒了。

TPO24 综合写作听力+阅读原文ReadingAnimal fossils usually provide very little opportunity to study the actual animal tissues, because in fossils the animals' living tissues have been largely replaced by minerals. Thus, scientists were very excited recently when it appeared that a70-million-year-old fossil of Tyrannosaurus rex (T. rex), a dinosaur, might still contain remains of the actual tissues of the animal. The discovery was made whenresearchers deliberately broke open the T. rex’s leg bone, thereby exposing its insides to reveal materials that seem to be remains of blood vessels, red blood cells, and collagen matrix.First, the breaking of the fossilized leg bone revealed many small branching channels inside, which probably correspond to hollows in the bones where blood vessels were once located. The exciting finding was the presence of a soft, flexible organic substance inside the channels. This soft substance may very well represent the remains of the actual blood vessels of T. rex.Second, microscopic examination of the various parts of the inner bone revealed the presence of spheres that could be the remains of red blood cells. Tests showed that the spheres contained iron-a material vital to the role of red blood cells in transporting oxygen to tissues. Moreover, the spheres had dark red centers (substances with iron tend to be reddish in color) and were also about the size of red blood cells.Third, scientists performed a test on the dinosaur leg bone that showed that it contained collagen. Collagen is a fibrous protein that is a main component of living bone tissue, in which it forms a so-called collagen matrix. Collagen (or its chemical derivatives) is exactly the kind of biochemical material that one would expect to find in association with bone tissue.ListeningAs much as we would like to have the remains of actual dinosaur tissue, there are sound reasons for being skeptical of the identifications made in the reading.First, the soft, flexible substance inside the bone channels isn’t necessarily the remains of blood vessels. It is much more likely to be something else. Like what? You might say. Well, long after an organism is died, bacteria sometimes colonize hollows, empty areas in bones, like the channels that once held blood vessels. When bacterialived inside bones, they often leave behind traces of organic material. What the researchers in the reading are identifying as blood vessels might just be traces of soft and moist residue left by bacteria colonies.All right. What about the iron-filled spheres? Well, the problem is that scientists found identical reddish spheres in fossils of other animals found in the same place. That includes fossils of primitive animals that did not have any red blood cells when they were alive. Clearly, if these spheres appear in organisms that did not have any red blood cells, then the spheres cannot be the remains of red blood cells. The spheres probably have a very different origin. They are probably just pieces of reddish mineral.Third, the collagen. The problem is that we have never found collagen in animal remains that are older than one hundred thousand years. Collagen probably cannot last longer than that. Finding collagen from an animal that lived seventy million years ago would really contradict our ideas about how long collagen can last. It is just too improbable. The most likely explanation for the presence of collagen is that it doesn’t come from the T.rex, but from another much more recent source. For example, human skin contains collagen, so the collagen may have come from the skin of the researchers who are handling the bone.由于篇幅有限，托福综合写作满分范文，在雷哥托福微信公众号获取。

托福听力TPO24原文Lecture3下面就让小编来为大家介绍一下托福听力TPO24原文中Lecture3的文本内容吧，大家要好好把握，这些都是非常有价值的材料，同时，大家也可以登录前程百利论坛进行TPO练习辅导，希望能够给准备托福听力的同学带来帮助。

TPO24Lecture3-Archaeology(Megafauna in North America)Professor：Between11,000and10,000B.C.E.,North America was populated by a wide variety of great beasts,like mammoth and mastodons,both elephant-like creatures with big tusks,and camels,giant sloths,the list goes on.By about10,000B.C.E.,all those giant creatures,the Metgauna of North America were gone.We don't know exactly what happened to them,but there are some theories.One theory is that they were hunted to extinction by humans.The humans who coexisted with these giant species in North America at that time were what we today called the Clovis Peopple.And there is a Clovis site in a valley in southern California where the remains of thirteen mammoths were found. And spear points,tools for processing meat,and fire places.That would appear to be some pretty compelling evidences.Mammoth bones have also been found at some other Clovis sites.But then at other Clovis sites,there's also a lot of evidence that the Clovis people mostly gather plants and hunted small game,like rabbits and wild turkeys.Also there are several places in North America where you have natural accumulations of mammoth bones that look very similar to the accumulations at the Clovis site,except there's no human debris,where the mammoth almost certainly died as a result of some kind of natural disaster.So I think it is quite likely that those thirteen mammoths in southern Californiaalso died of natural causes,and that the Clovis people simply took advantage of the situation.Um...OK.That's the hunting theory.Now let's look at another theory,uh,an alternative to the hunting theory,the climate change theory.At around11,500B.C.E.，the world was coming out of an Ice Age.And with that came increased seasonality,that is,the summers became warmer,and the winters actually became colder.These extreme shifts would have put a lot of stress on the bodies of animals that were used to a more moderate range of temperatures.But the most important impact of this increased seasonality may very well have been its effect on the distribution of plants.Today we take for granted that there horizontal bands of plant communities.In the far north,it is tundra,which gives way to forest as you move southward.And even farther south,grasslands take over.But during the Ice Age,these plant communities actually grew together,mixed with one another.So Ice Age animals had access to many different types of plants,different types of food.But when the seasons became more distinct,the plant communities were pulled apart,that meant,in any given area,there was less plant diversity.And as a result,uh,so the theory goes,the Ice Age animals that depended on plant diversity couldn't survive.And the great beasts were the ones that needed the most diversity in their diet.Again,we have what at first seems like a pretty attractive theory,but then,how do you explain the fact that this has happened before?You know,global cooling followed by global warming,and there was no extinction then.Uh,you know,I recently read an interesting article about an archaeologist who tried to solve this puzzle with the help of his computer.What he did was,he wrote a computerprogram to simulate what would happen to mammoth under certain conditions.Say,for example,there is a drought for a couple of decades,or hunters are killing or five percent of the population,and so on.One thing he found was that humans didn't necessarily have to kill these animals in great numbers in order to nudge them toward extinction.That's because very large animals have a slow rate of reproduction,so all you have to do is remove a few young females from the herd,and you can,fairly quickly,significantly reduce the population.And then he came up with a scenario that combined some hunting by humans with some environmental stress,and...Bang!The simulated mammoths were extinct within decades.So it seems the mixture of hunting and climate change is a likely scenario.Uh,of course,computer simulations are not a substitute for hard evidence.教授：在公元前11000年到10000年前，北美洲生活着各种大型的生物，比如猛犸和乳齿象，两种都是象类的生物，都有巨大的长牙，驼峰和大地懒和其他特征。

Moving into PueblosIn the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.Given all the disadvantages of living in aggregated towns, why did people in the thirteenth century move into these closely packed quarters? For transitions of such suddenness, archaeologists consider either pull factors (benefits that drew families together) or push factors (some external threat or crisis that forced people to aggregate). In this case, push explanations dominate.Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.Paragraph1: In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.○Essential○highly stressful○highly unusual○unwise○strong○questionable○obvious○deliberate3.According to paragraph 1, before the thirteenth century the people of southwestern North America livedin households that○shar ed daily chores with neighboring households○occupied dwellings that were built into the sides of cliffs○were largely free to conduct their lives as they pleased○enforced common standards of behavior and cooperative conduct within their communities4.Which of the following best indicates the organization of paragraph 1?○It presents the conditions that caused a change in a population' s living patterns and then explains why those conditions got worse.○It identifies certain present-day cultural traditions and rules and then traces them to their roots in the thirteenth century.○It casts doubt on one explanation of the move to pueblos and then introduces an alternative explanation that the passage will defend.○It describes a major change in a pop ulation' s living patterns and then presents a number of problems that resulted from that change.paragraph3: Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.5. According to paragraph 3, which of the following was one of the consequences of increasing population densities?○People were in creasingly crowded into collections of large housing units.○People stopped planting crops that have relatively low yields.○Domestic buildings were pushed beyond the canyon limits.○The natural landscape was destroyed.6. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage?Incorrect choices change the meaning in important ways or leave out essential information.○Some scholars even claim that the intensification of farmers' various efforts during the 1200s led to further population growth and the consequent need for more arable land.○Evidence of intensifying agriculture in the 1200s indicates a need to feed a larger population and soextends the argument that a growing population was the cause of the move to pueblos.○During the 1200s, farmers met the demand for more arable land, but they also succeeded in cultivating existing land more intensively with the help of agricultural construction projects.○Some scholars feel strongly that the con struction of small dams, reservoirs, terraces, and field houses in the thirteenth century is independent evidence for growth in the number of people.paragraph4: Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.7.○change○climate○decline○problem8. Why does the author state that "Growing food at these elevations is always difficult because of the short growing season"?○To explain why the higher elevations were always relatively sparsely populated○To suggest that any worsening of conditions would have significant consequences○To emphasize how resourceful the people gro wing food at these elevations were○To argue that farming was not the primary source of food at high elevations9. According to paragraph 4, what did farmers do in response to falling temperatures during the Little Ice Age?○Moved to areas away fro m Mesa Verde○Moved closer to the northeastern part of Mesa Verde○Began to cultivate crops adapted to a short growing season○Gave up the cultivation of the highest-lying landsparagraph5: In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonialevents were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.10. According to paragraph 5, major ceremonial events were occasions for○leaders to persuade people from the countryside to move into a pueblo○farmers to collect information about where crops could be reliably grown○people to develop better techniques for producing pottery and crafts○people in the early Puebloan era to share farm and craft products11. According to paragraph 5, which of the following was a reason people in the Mesa Verde area formed communal villages in the thirteenth century?○The climate in the Mesa Verde area became more locally diverse.○Individuals were no longer interested in exchanging pottery and food.○Cooperatio n between people became more important for survival.○Bad years of farming began to occur more frequently.12. Paragraph 5 supports which of the following statements about cooperation among the people in the Mesa Verde area from the eleventh through the thirteenth century?○ Cooperation allowed many households to give up farming and to specialize in making pottery and crafts.○People went from exchanging food and crafts they individually produced to sharing in a cooperative effort to produce as much food as possible.○ Overtime there was less cooperation as farmers competed with each other for trade with distant areas.○ Individuals stopped cooperating with each other because they did not have enough food for themselves.paragraph1: In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. [■] And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. [■] For people in cliff dwel lings, hauling water, wood, and food to their homes was a major chore. [■] The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic. [■]13. Look at the four squares [■] that indicate where the following sentence could be added to the passage.Performing everyday household tasks required more effort.Where would the sentence best fit? Click on a square to add the sentence to the passage.14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage.This question is worth 2 points.In the thirteenth century, the people in the Mesa Verde area went from living in scattered independent households to living in large pueblos.●●●Answer Choices○ Because the thirteenth-century inhabitants of the Mesa Verde area did not have the cultural expectations of today's city dwellers, they easily adapted to communal life.○ Even though living in pueblos had disadvantages, the population of the area had grown so large that there may have been no other arrangement that would have met its needs.○ From the eleventh century onward, farmers began to increase food production on existing farmland and started bringing more land under cultivation.○ A development that contributed to increasing population densities was a cooling climate that led many people to leave the coldest areas and crowd into climatically more favorable areas.○ The primary reason for moving to pueblos was the social benefits associated with communal life.○ People were brought together by the need to produce food cooperatively, as the use of food surpluses inone place to relieve shortages in another ended due to a change in climate.参考答案:1.22.13.34.45.16.27.18.29.410. 411. 312. 213. 214. A development that...The primary reason...People were brought...正确版如下：。

Moving into PueblosIn the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.Given all the disadvantages of living in aggregated towns, why did people in the thirteenth century move into these closely packed quarters For transitions of such suddenness, archaeologists consider either pull factors (benefits that drew families together) or push factors (some external threat or crisis that forced people to aggregate). In this case, push explanations dominate.Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.In the face of all these pushes, people in the Mesa V erde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperationallowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.Paragraph1: In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.○highly stressful○highly unusual○unwise○questionable○obvious○deliberateto paragraph 1, before the thirteenth century the people of southwestern North America lived in households that ○shared daily chores with neighboring households○occupied dwellings that were built into the s ides of cliffs○were largely free to conduct their lives as they pleased○enforced common standards of behavior and cooperative conduct within their communitiesof the following best indicates the organization of paragraph 1○It presents the condi tions that caused a change in a population' s living patterns and then explains why those conditions got worse.○It identifies certain present-day cultural traditions and rules and then traces them to their roots in the thirteenth century.○It casts doubt on one explanation of the move to pueblos and then introduces an alternative explanation that the passage will defend.○It describes a major change in a population' s living patterns and then presents a number of problems that resulted from that change.paragraph3: Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.5. According to paragraph 3, which of the following was one of the consequences of increasing population densities○People were increas ingly crowded into collections of large housing units.○People stopped planting crops that have relatively low yields.○Domestic buildings were pushed beyond the canyon limits.○The natural landscape was destroyed.6. Which of the sentences below best expresses the essential information in the highlighted sentence in the passageIncorrect choices change the meaning in important ways or leave out essential information.○Some scholars even claim that the intensification of farmers' various efforts during the 1200s led to further population growth and the consequent need for more arable land.○Evidence of intensifying agriculture in the 1200s indicates a need to feed a larger population and so extends the argument that a growing population was the cause of the move to pueblos.○During the 1200s, farmers met the demand for more arable land, but they also succeeded in cultivating existing land more intensively with the help of agricultural construction projects.○Some scholars feel strongly that the construct ion of small dams, reservoirs, terraces, and field houses in the thirteenth century is independent evidence for growth in the number of people.paragraph4: Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.7.○change○climate○decline○problem8. Why does the author state that "Growing food at these elevations is always difficult because of the short growing season"○To explain why the higher elevations were always relatively sparsely populated○To suggest that any worsening of conditions would have significant consequences○To emphasize how resourceful the people growing food a t these elevations were○To argue that farming was not the primary source of food at high elevations9. According to paragraph 4, what did farmers do in response to falling temperatures during the Little Ice Age○Moved to areas away from Mesa Verde○Moved closer to the northeastern part of Mesa Verde○Began to cultivate crops adapted to a short growing season○Gave up the cultivation of the highest-lying landsparagraph5: In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.10. According to paragraph 5, major ceremonial events were occasions for○leaders to persuade people from the countryside to move into a pueblo○farmers to collect information about where crops could be reliably grown○people to develop better techniques for producing pottery and crafts○people in the early Puebloan era to share farm and craft products11. According to paragraph 5, which of the following was a reason people in the Mesa Verde area formed communal villages in the thirteenth century○The climate in the Mesa Verde area became more locally diverse.○Individuals were no longer interested in exchanging pottery and food.○Cooperation between people became more important for survival.○Bad years of f arming began to occur more frequently.12. Paragraph 5 supports which of the following statements about cooperation among the people in the Mesa Verde area from the eleventh through the thirteenth century○ Cooperation allowed many households to give up farming and to specialize in making pottery and crafts.○People went from exchanging food and crafts they individually produced to sharing in a cooperative effort to produce as much food as possible.○ Overtime there was less cooperation as farmers comp eted with each other for trade with distant areas.○ Individuals stopped cooperating with each other because they did not have enough food for themselves.paragraph1: In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. [■] And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. [■] For people in cliff dwellings, hauling water, wood, and food to their homes was a major chor e. [■] The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic. [■]13. Look at the four squares [■] that indicate where the follow ing sentence could be added to the passage.Performing everyday household tasks required more effort.Where would the sentence best fit Click on a square to add the sentence to the passage.14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the question is worth 2 points.In the thirteenth century, the people in the Mesa Verde area went from living in scattered independent households to living in large pueblos.●●●Answer Choices○ Because the thirteenth-century inhabitants of the Mesa V erde area did not have the cultural expectations of today's city dwellers, they easily adapted to communal life.○ Even though living in pueblos had disadvantages, the population of the area had grown so large that there may have been no other arrangement that would have met its needs.○ From the eleventh century onward, farmers began to increase food production on existing farmland and started bringing more land under cultivation.○ A development that contributed to increasing population densities was a cooling climate that led many people to leave the coldest areas and crowd into climatically more favorable areas.○ The primary reason for moving to pueblos was the social benefits associated with communal life.○ People were brought together by the need to produce food cooperatively, as the use of food surpluses in one place to relieve shortages in another ended due to a change in climate.参考答案:1.22.13.34.45.16.27.18.29.410.411.312.213.214. A development that...The primary reason...People were brought...正确版如下：。

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托福TPO24口语Task4阅读文本： Flagship Species Environmental organizations work to protect plants and animals whose natural habitats are threatened by human activity. One way they do this is by selecting a particular species to represent the threatened habitat to the general public. This species, called a flagship species, is one that people are likely to find attractive and interesting. The flagship species is used to raise public awareness and motivate people to take action to protect the threatened habitat. People’s support of the flagship species results in protection for all the plant and animal species living in the threatened area. 托福TPO24口语Task4听力文本： Now listen to part of a lecture on this topic in an environmental science class. (male professor) So, one example of this is the macaw, the great green macaw. Now, the great green macaw is a beautiful bird, a fairly large-sized parrot known for its colorful feathers, gorgeous green feathers with some read and blue feathers, too. The macaw lives in the South American rainforest, in a part of the rainforest where a lot of trees have been cut down, trees that the macaw relies on for its food and nesting. So, the macaw was in trouble.And, of course, along with the trees, a lot of other animals were in trouble, too. Lots of birds, bats, and frogs also live in these trees. So, when the trees were cut down and cleared away, these animals also didn't have a place to live anymore and their populations drastically declined. So, what a concerned group of people in the area did was they started spreading the word about how the macaw, you know this really beautiful bird, needed help.They made little books with information about the macaw, with pictures, full colored pictures of the macaw that showed off its beautiful feathers, and they passed out these little books, these informational brochures. They distributed them to people in schools and community centers in the area. And a lot of people responded. They contributed money, and helped the group set up some protected land, a special area where no one could cut down the trees, so the macaw would be safe. And the macaw’s population started to increase and other birds and bats and frogs came back to the area, too. Their numbers increased along with the trees. 托福TPO24口语Task4题目： Using the example of the macaw from the lecture, explain the concept of a flagship species. 托福TPO24口语Task4满分范文： Flagship species is a particular kind of species that people select to represent an endangered habitat in order to protect that habitat. For example, great green macaw, a very beautiful bird that lives in a part of South American Forests. And since many trees that the bird rely on for food and nesting have been cut down, the great green macaw was in trouble, and the number of many other species in the area also decreases. Because the macaw has nice feathers, a group of people who are concerned with the issue choose it to represent the habitat. They spread the words that the beautiful bird is in danger to the general public and give out brochures with its picture printed on them. With the help of the flagship species, the public becomes aware of the situation and begins to respond by donating money or setting up non-cutting zones to help preserve the forest. With these efforts, the habitat is saved and the number of other species living on the land grows back, too. (172 words) 以上是给大家整理的托福TPO24口语Task4阅读文本+听力文本+题目+满分范文，希望对你有所帮助!。

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TPO24Lecture4-Astronomy(Shield Volcanoes on Venus)Professor：Many people have been fascinated about Venus for centuries because of its thick cloud cover,this so-called planet of mystery and all of that.Well,what's under those clouds?What's the surface of the planet like?Some questions about the surface are still unresolved but,but we have learned a lot about it in the past several years.First of all,let me talk about how we have been able to get past those clouds.First,there were Soviet modules2that landed directly on the surface and sent back some images ofwhat was around them.Second,we did some radar imaging from satellites from above.Radar can get through the clouds.So what have we learned?Yes,Karen?Student：Well,I remember reading that there's not really a lot going on,that the surface of Venus is just flat and smooth in a lot of places.Professor：Yeah,smooth in a lot of places.But that's not,um...that's not the whole picture.In other areas,you've got canyons,ripped valleys,meteo craters,uh,lava domes, these lava formations that look like giant pancakes.And also volcanoes.Well,one of the most interesting features on the surface are in fact the shield volcanoes.Shield volcanoes formed when magma comes out of the ground in the same spot over and over again.Remember, magma is hot molten rock that's underground,and it is called lava when it reaches the surface. Uh,so the lava builds up,and hardens,and a volcano forms.Now,the lava on Venus is thin. It spreads out easily.So shield volcanoes have very gentle sloping sides.They are called shield volcanoes,because viewed from above,they kind of resemble shields,you know,like a warrior's shield.But what's particularly interesting about these volcanoes is that most of the volcanoes here on Earth are not shield volcanoes.Instead,they are other volcano types,like strata volcanoes,for example,which are a result of tectonic plate movement. Remember tectonic plates?Underneath the Earth's crust,there are a number of shifting slabs or plates that are slowly moving.And in the zones on the edges of the plates where differentplates meet and interact,that's where we get most of Earth's volcanoesOn Venus,however, volcanoes are not clustered in discrete zones like they are on Earth.Instead,they are more or less randomly scattered over Venus's surface.Well,that's significant.Venus has mostly shield volcanoes,and they are randomly scattered,that indicates that Venus does not have moving tectonic plates,and that's a big difference compared to Earth.Here on Earth,moving tectonic plates are a major geological element,just crucial for the whole surface dynamic,right?So why doesn't Venus have them?Well,there are a few theories.One of them is that this has to do with the fact that Venus has no surface water that's needed to kind of lubricate the movement of the plates,you know,like oceans on Earth.Yeah,I forgot to spell that out.Uh,Venus has no surface water.Student：Wait a second.Did you say we have shield volcanoes on Earth?Can you give an example?Professor：Sure.The volcanoes in the Hawaii islands,in the Pacific Ocean are shield volcanoes.They are formed over a hot spot of magma.So while on Earth we have several types of volcanoes,on Venus there's mostly the one type.Uh,Eric?Student：Are the volcanoes on Venus still active?Professor：Well,that's an interesting question.There is still some discussion on that point.But here's what we do now.First,the level of sulfur dioxide gas above Venus's clouds shows large and very frequent fluctuations.It is quite possible that these fluctuations, the huge increase and decrease of sulfur dioxide,happening again and again.It's quite possible that this is due to volcanic eruptions,because volcanic eruptions often emit gases. If that's the case,volcanism could very well be the root cause of Venus's thick cloud cover. And also we have observed bursts of radio energy from the planet's surface.These bursts are similar to what we see when volcanoes erupt on Earth.So this too suggests ongoing volcanic activity.But although this is intriguing evidence,no one's actually observed a Venus volcano erupting yet,so we can't be positive.教授：几个世纪来许多人都对厚云层覆盖的金星有着深厚的兴趣，它被称之为神秘的星球。