TPO51托福阅读passage3：The Role of the Ocean in Controlling Climate原文文本+真题答案

托福阅读真题第51篇E1NinoandtheSouthernOscillationBetween the ocean surface and the atmosphere. there is an exchange of heat and moisture that depends, in pat, on temperature differences between water and air. Even a relatively small change in surface ocean temperatures could modify atmospheric circulations and have far-reaching effects on global weather patterns.Along the west coast of South America, where the cool Peru Current sweeps northward,southerly winds promote upwelling (rising to the surface and flowing outward ) of cold.nutrient- rich water that gives rise to large fish populations. especially anchovies. The abundance of fish supports a large population of seabirds whose droppings (ale guano) produce huge phosphate rich- deposits that support the fertilizer industry. Near the end of the calendar year, a warm current of nutrient-poor tropical water often moves southward, replacing the cold, nutrient-rich surface water.In most years, the warming lasts for only a few weeks to a month or more, after which weather patterns usually return to normal and fishing improves. However, when conditions last for many months, and a more extensive ocean warming occurs, the economic results can be catastrophic. This extremely warm episode, which occurs at irregular intervals of two to seven years and covers a large area of the tropical Pacific Ocean, is now referred to as a major El Nino event, or simply El Nino.During a major El Nino event, large numbers of fish and marine plants may die. Dead fish and birds may litter the water and beaches of Peru; their decomposing bodies reduce the water's oxygen supply,which leads to the bacterial production ofhuge amounts of hydrogen sulfide. The El Nino of 1972-1973 reduced the annual Peruvian anchovy catch from 10.3 million metric tons in 1971 to 4.6 million metric tons in 1972. Since much of the harvest of this fish is converted into fish meal and exported for use in feeding livestock and poultry, the world's meal production in 1972 was greatly reduced. Countries such as the United States that rely on meal for animal feed had to use soybeans as an alternative This raised poultry prices in the United States by more than 40 percent.Why does the ocean become so warm over the eastern tropical Pacific? Normally in the tropical Pacific Ocean, there are the trades-persistent winds that blow westward from a region of higher pres sure over the eastern Pacific toward a region of lower pressure centered near Indonesia. The trades create upwelling that brings cold water to the surface.As this water moves westward, it is heated by sunlight and the atmosphere.Consequently, in the Pacific Ocean,surface water along the equator usually is cool in the east and warm in the west. In addition, the dragging of surface water by the trades raises the sea level in the western Pacific and lowers it in the eastern Pacific, which produces a thick layer of warm water over the tropical western Pacific Ocean and a weak ocean current (called the counter current) that flows slowly eastward toward South America.Every few years, the surface atmospheric pressure patterns break down, as air pressure rises over the region of the western Pacific and falls over the eastern Pacific. This change in pressure weakens the trades, and, during strong pressure reversals, east winds are replaced by west winds. The west winds strengthen the counter current, causing warm water to head eastward towardSouth America over broad areas of the tropical Pacific. Toward the end of the warming period, which may last between one and two years, atmospheric pressure over the eastern Pacific reverses and begins to rise, whereas, over the western Pacific, it falls. This seesaw pattern of reversing surface air pressure at opposite ends of the Pacific Ocean is called the Southern Oscillation. Because the pressure reversals and ocean warming are more or less simultaneous, scientists call this phenomenon the El Nino/Southern Oscillation, or ENSO for short. Although most ENSO episodes follow similar evolution, each event has its own personality, differing in both strength and behavior.1.Between the ocean surface and the atmosphere. there is an exchange of heat and moisture that depends, in pat, on temperature differences between water and air. Even a relatively small change in surface ocean temperatures could modify atmospheric circulations and have far-reaching effects on global weather patterns.。

托福TPO真题阅读答案解析托福TPO真题阅读答案解析只有愚者才等待机会，而智者则造就机会。

下面是店铺为大家搜索整理的托福TPO真题阅读答案解析，希望大家能有所收获，l 答案及题目解析Key:1.B2.A3.C4.C5.A6.B7.D8.D9.B10.C 11.D 12.B 13-14.125题目解析：1. In paragraph 1, what does the author say about the presence of a blowhole in cetaceans?(Factual Information Question)A.It clearly indicates that cetaceans are mammals.B.It cannot conceal the fact that cetaceans are mammals.C.It is the main difference between cetaceans and land-dwelling mammals.D.It cannot yield clues about the origins of cetaceans.相关原句：Their streamlined bodies, the absence of hind legs, and the presence ofa fluke and blowhole cannot disguise their affinities with land dwelling mammals.(Paragraph 1)本题解析：cannot disguise…意为“不能掩盖…”，因此“the presence of blowhole cannot disguise their affinities with land dwelling mammals”意思是“具有blowhol(出气孔)并不能掩盖这一事实：鲸类动物和陆栖哺乳动物有姻亲关系(affinities)”;B选项中cannot concea(不能隐藏)l恰好与 cannot disguise相吻合，并指出鲸类动物是哺乳动物的事实，因此选择B。

托福听力tpo51 全套对话讲座原文+题目+答案+译文Section 1 (2)Conversation1 (2)原文 (2)题目 (4)答案 (5)译文 (5)Lecture1 (7)原文 (7)题目 (9)答案 (11)译文 (11)Lecture2 (13)原文 (13)题目 (16)答案 (18)译文 (18)Section 2 (20)Conversation2 (20)原文 (20)题目 (22)答案 (24)译文 (24)Lecture3 (26)原文 (26)题目 (28)答案 (30)译文 (30)Lecture4 (32)原文 (32)题目 (34)答案 (36)译文 (36)Section 1Conversation1原文NARRATOR: Listen to part of a conversation between a student and her biology professor.MALE PROFESSOR: So the assignment is to reproduce one of the animal camouflage experiments we read about in our text book. Which experiment did you pick? FEMALE STUDENT: Well... I was wondering if I could try to reproduce an experiment that's kinda the opposite of what was discussed in the textbook?MALE PROFESSOR: So, instead of how and why an animal might hide itself, you want to do something about why an animal might want to be seen? Hmmm. Tell me more. FEMALE STUDENT: Well, I got the idea from one of the journals you said we should look at…it's an experiment about, um, they called them eyespots in the article? MALE PROFESSOR: Eyespots, sure, the patterns on the wings of moths and butterflies that are generally believed to scare off predators because they look like big eyes. FEMALE STUDENT: Yeah, except the article was about an experiment that disputes that theory.MALE PROFESSOR: Well, we know that the markings do scare the birds, but the idea that the spots look like eyes is, well that's just a commonly held belief.FEMALE STUDENT: So—that's not even based on research?MALE PROFESSOR: Well, this whole idea of moth or butterfly markings being scary because they look like eyes rests on how we imagine that their predators—like birds —perceive the markings. And we can never really know that. All we can do is observe bird behavior. But tell me more about the experiment.FEMALE STUDENT: OK, so the experiment looked at the shapes of the markings onmoth wings. The researchers wanted to know if the markings that were round or eye-shaped were more effective at deterring predators than square or rectangular markings.MALE PROFESSOR: OK…FEMALE STUDENT: Yeah. So, they attached food to paper models of moths, with different shaped marks drawn on the wings, to see how birds reacted. And what's interesting is, they realized that the round marks were not more effective at scaring birds than other shapes.MALE PROFESSOR: Were they less effective?FEMALE STUDENT: No, they were about the same... but what researchers did determine is that larger markings are more effective than smaller markings at scaring off prey. They called this phenomenon “visual loudness.”MALE PROFESSOR: Visual loudness, huh. Well, I guess it's not all that shocking, if you think about it.FEMALE STUDENT: So, anyway, is it OK? Can I repeat this experiment and write about it?MALE PROFESSOR: Yes, I think that'll work. The problem I foresee is, well, where? This is an urban campus...You'll have a hard time finding a good place to set up the experiment.FEMALE STUDENT: Oh, I-I wasn't planning on doing it on campus. I'm going home for spring break, and my family lives in the country, far from the nearest city. I can set it up in the backyard.MALE PROFESSOR: Good idea. Except one week is not a lot of time. So you'll need to make some adjustments to have enough data. I'd set up the experiment near a bird feeder, and get in as much observation time as you can.题目1.Why does the student talk with the professor?A. She wants permission to revise an experiment that she conducted earlier.B. She has a question about the findings of an experiment in the textbook.C. She wants to reproduce an experiment that is not in the textbook.D. She would like some advice about how to study butterfly and moth behavior.2.What does the professor say is a common assumption about certain markings on butterfly and moth wings?A. That the markings are usually hidden from viewB. That the markings attract some kinds of birds more than othersC. That some birds perceive the markings as large eyesD. That butterflies and moths use the markings to attract mates3.What were the results of the experiment that the student describes? [Click on 2 answers.]A. Birds reacted to round markings the same way they reacted to square markings.B. Large markings scared birds more than small markings did.C. Most birds ignored markings that looked like eyes.D. Birds were attracted to more colorful markings.4.Why does the professor mention a bird feeder?A. To suggest a strategy that may help the student carry out her task successfullyB. To recommend a place on campus that is suitable for the student's projectC. To discuss another experiment that has yielded surprising resultsD. To point out a problem in the design of the original experiment5.What can be inferred about the student when she says this:Professor: Well, we know that the markings do scare the birds but the idea that the spots looked like eyes is……well, that is just a commonly held belief.Student: So, that’s not even based on research?A. She is skeptical about what the professor just told her.B. She just realized that she designed her experiment incorrectly.C. She is worried that she misunderstood something that she read.D. She had assumed that there was scientific evidence for the theory.答案C C AB A D译文旁白：请听一段学生和其生物学教授之间的对话。

TPO51托福阅读passage3:The Role of the Oceanin Controlling Climate原文文本+真题答案第三篇：社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one ofthe most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming —adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calculations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming—adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.2.The word “principally”in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.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.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The word “controversial”in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce”in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how might increasing phytoplankton growth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the ocean’s surface to deeper levelsParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbon dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.9.The word “fuels”in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores heatB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More of the Sun’s radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflectedParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. ■However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. ■What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. ■Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. ■Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased oceantemperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares [■] that indicate where the following sentence could be added to the passageNor is carbon dioxide the only gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the air through limestone production and photosynthesis or phytoplankton.C.Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming.D.The ocean's capacity to absorb carbon dioxide remains great despite recent reduction of marine plant nutrients such as iron.E.Ocean circulation is strongly controlled by wind and by the sea s balance or salt and heat.F.The ocean bolds and moves a great deal of heat, and as waterevaporates, it produces clouds, snow, and ice, which all affect global temperatures.参考答案1-5：DCACB6-10：CBDAC11-13：BAC14：BCF文章来源：雷哥托福。

TPO51托福独立写作真题阅读与听力材料及参考范文【雷哥托福】托福TPO51独立写作Do you agree or disagree with the following statement?When classmates or colleagues communicate about a project in person instead of by e-mail, they will produce better work for the project.Use specific reasons and examples to support your answer.参考范文:With the convenience of e-mail today, many people have gone from working on projects in person to collaborating over e-mail. Is this a positive change? I do not think so.First of all，while working via e-mail may be convenient for when meeting in person is difficult. E-mails are not conducive to some aspects of collaboration. Group brainstorming, for example, works much better when everybody can voice their ideas in person. Brainstorming is a fast and dynamic process. Ideas are quickly generated and discarded. A brainstorming session might normally take an hour to conduct in person, but the process could drag on for several days over e-mail. Plus, not everybody checks their e-mail consistently, so some people might miss out on parts of the brainstorming process.Second of all, e-mail conveys tone and body language very poorly. Misunderstandings can arise more easily when only using e-mail to collaborate. I remember working on a school project once with classmates I wasn’t close with. We all lived very far apart, so e-mail became our main means of communication.However, because we didn’t really take die time to get to know each other in person, there was a lot of miscommunication. For example, people quickly became annoyed at the group leader because his e-mails sounded like orders. In reality he was a reasonable guy，but he didn’t know any of us so he wanted to be clear and direct about everybody，s responsibilities. If we had simply talked things over in person this never would have been an issue.Granted, today e-mail is a necessary tool in almost any group project. It makes collaborating much more flexible, because groins can stay in touch even when they aren't assembled in one place. But e-mail can't replace working together face-to-face. At best, it can serve as a supplementary tool to keep people updated on projects. Whether it’s brainstorming ideas or rehearsing a presentation, large parts of the collaborative process benefit from having everyone physically present. Not to mention, some people absorb information best when they see and hear explanations. We would never suggest, for example, that teachers teach by sending e-mails instead of lecturing in classrooms. So e-mail may not be the most effective way for people to exchange information during projects, E-mail is a wonderful invention that has changed the way people communicate. However, in some areas of life, it will never be as effective as face-to-face communication. When working on projects, it is still better to collaborate in person.来源：雷哥托福。

托福阅读TPO3(试题+答案+译文)第3篇:TheLong-TermStabilityofEcosystems为了帮助大家备考托福。

提高阅读成绩，打有准备的仗，下面小编给大家带来托福阅读TPO3(试题+答案+译文)第3篇:The Long-Term Stability of Ecosystems，希望大家喜欢。

托福阅读原文Plant communities assemble themselvesflexibly, and their particular structure depends on the specific history of thearea. Ecologists use the term “succession” to refer to the changes that happenin plant communities and ecosystems over time. The first community in asuccession is called a pioneer community, while the long-lived community at theend of succession is called a climax community. Pioneer and successional plantcommunities are said to change over periods from 1 to 500 years. Thesechanges—in plant numbers and the mix of species—are cumulative. Climaxcommunities themselves change but over periods of time greater than about 500years.An ecologist who studies a pond today maywell find it relatively unchanged in a year’s time. Individual fish may bereplaced, but the number of fish will tend to be the same from one year to thenext. We can say that the properties of an ecosystem are more stable than theindividual organisms that compose the ecosystem.At one time, ecologists believed that speciesdiversity made ecosystems stable. They believed that the greater the diversitythe more stable the ecosystem. Support for this idea came from the observationthat long-lasting climax communities usually have more complex food webs andmore species diversity than pioneer communities. Ecologists concluded that theapparent stability ofclimax ecosystems depended on their complexity. T o takean extreme example, farmlands dominated by a single crop are so unstable thatone year of bad weather or the invasion of a single pest can destroy the entirecrop. In contrast, a complex climax community, such as a temperate forest, willtolerate considerable damage from weather to pests.The question of ecosystem stability iscomplicated, however. The first problem is that ecologists do not all agreewhat “stability”means. Stability can be defined as simply lack of change. Inthat case, the climax community would be considered the most stable, since, bydefinition, it changes the least over time. Alternatively, stability can bedefined as the speed with which an ecosystem returns to a particular formfollowing a major disturbance, such as a fire. This kind of stability is alsocalled resilience. In that case, climax communities would be the most fragileand the least stable, since they can require hundreds of years to return to theclimax state.Even the kind of stability defined assimple lack of change is not always associated with maximum diversity. At leastin temperate zones, maximum diversity is often found in mid-successionalstages, not in the climax community. Once a redwood forest matures, forexample, the kinds of species and the number of individuals growing on theforest floor are reduced. In general, diversity, by itself, does not ensurestability. Mathematical models of ecosystems likewise suggest that diversitydoes not guarantee ecosystem stability—just the opposite, in fact. A morecomplicated system is, in general, more likely than a simple system to breakdown. A fifteen-speed racing bicycle is more likely to break down than achild’s tricycle.Ecologists are especially interested toknow what factorscontribute to the resilience of communities because climaxcommunities all over the world are being severely damaged or destroyed by humanactivities. The destruction caused by the volcanic explosion of Mount St.Helens, in the northwestern United States, for example, pales in comparison tothe destruction caused by humans. We need to know what aspects of a communityare most important to the community’s resistance to destruction, as well as itsrecovery.Many ecologists now think that the relativelong-term stability of climax communities comes not from diversity but from the“patchiness” of the environment, an environment that varies from place to placesupports more kinds of organisms than an environment that is uniform. A localpopulation that goes extinct is quickly replaced by immigrants from an adjacentcommunity. Even if the new population is of a different species, it canapproximately fill the niche vacated by the extinct population and keep thefood web intact.托福阅读试题1. The word “particular”in the passage(paragraph 1) is closest in meaning toA.naturalB.finalC.specificplex2. According to paragraph 1, which of thefollowing is NOT true of climax communities?A.They occur at the end of a succession.B.They last longer than any other type ofcommunity.C.The numbers of plants in them and the mixof species do not change.D.They remain stable for at least 500 yearsat a time.3. According to paragraph 2, which of thefollowing principles of ecosystems can be learned bystudying a pond?A.Ecosystem properties change more slowlythan individuals in the system.B.The stability of an ecosystem tends tochange as individuals are replaced.C.Individual organisms are stable from oneyear to the next.D.A change in the members of an organismdoes not affect an ecosystem’s properties.4. According to paragraph 3, ecologistsonce believed that which of the following illustratedthe most stableecosystems?A.Pioneer communitiesB.Climax communitiesC.Single-crop farmlandsD.Successional plant communities5. According to paragraph 4, why is thequestion of ecosystem stability complicated?A.The reasons for ecosystem change are notalways clear.B.Ecologists often confuse the word“stability”with the word “resilience.”C.The exact meaning of the word “stability”is debated by ecologists.D.There are many different answers toecological questions.6. According to paragraph 4, which of thefollowing is true of climax communities?A.They are more resilient than pioneercommunities.B.They can be considered both the most andthe least stable communities.C.They are stable because they recoverquickly after majordisturbances.D.They are the most resilient communitiesbecause they change the least over time.7. Which of the following can be inferredfrom paragraph 5 about redwood forests?A.They become less stable as they mature.B.They support many species when they reachclimax.C.They are found in temperate zones.D.They have reduced diversity duringmid-successional stages.8. The word “guarantee”in the passage(paragraph 5) is closest in meaning toA.increaseB.ensureC.favorplicate9. In paragraph 5, why does the authorprovide the information that “A fifteen-speed racing bicycle is more likely tobreak down than a child’s tricycle”?A.To illustrate a general principle aboutthe stability of systems by using an everyday exampleB.To demonstrate that an understanding ofstability in ecosystems can be applied to help understand stability in othersituationsC.To make a comparison that supports theclaim that, in general, stability increases with diversityD.To provide an example that contradictsmathematical models of ecosystems10. The word “pales” in the passage(paragraph 6) is closest in meaning toA.increases proportionallyB.differsC.loses significanceD.is common11. Which of the sentences below bestexpresses the essential information in the highlighted sentence in the passage(paragraph 7)? Incurred choices change the meaning in important ways or leaveout essential information.A.Ecologists now think that the stabilityof an environment is a result of diversity rather than patchiness.B.Patchy environments that vary from placeto place do not often have high species diversity.C.Uniform environments cannot be climaxcommunities because they do not support as many types of organisms as patchyenvironments.D.A patchy environment is thought toincrease stability because it is able to support a wide variety of organisms.12. The word “adjacent”in the passage(paragraph 7) is closest in meaning toA.foreignB.stableC.fluidD.neighboring13. Look at the four squares [█] thatindicate where the following sentence could be added to the passage. In fact,damage to the environment by humans is often much more severe than damage bynatural events and processes.█【A】Ecologists are especially interested to know what factors contributeto the resilience of communities because climax communities all over the worldare being severelydamaged or destroyed by human activities. █【B】The destructioncaused by the volcanic explosion of Mount St. Helens, in the northwesternUnited States, for example, pales in comparison to the destruction caused byhumans. █【C】We need toknow what aspects of a community are most important to the community’sresistance to destruction, as well as its recovery. █【D】Where would the sentence best fit? Click ona square to add the sentence to the passage.14. Directions: Anintroductory sentence for a brief summary of the passage is provided plete the summary by selecting the THREE answer choices that express themost important ideas in the passage. Some sentences do not belong in thesummary because they express ideas that are not presented in the passage or areminor ideas in the passage. This question is worth 2 points.The process of succession and the stabilityof a climax community can change over time.A.The changes that occur in an ecosystemfrom the pioneer to the climax community can be seen in one human generation.B.A high degree of species diversity doesnot always result in a stable ecosystem.C.The level of resilience in a plantcommunity contributes to its long-term stability.D.Ecologists agree that climax communitiesare the most stable types of ecosystems.E.Disagreements over the meaning of theterm “stability”make it difficult to identify the most stable ecosystems.F.The resilience of climax communitiesmakes them resistant to destruction caused by humans.托福阅读答案1. particular特别的，特定的，答案specific。

TPO51托福阅读passage3:The Role of the Oceanin Controlling Climate原文文本+真题答案第三篇：社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that inareas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming —adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies theprecipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects ofclimate that are not well understood—one of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calculations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming—adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.2.The word “principally”in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.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.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The word “controversial”in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce”in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how might increasing phytoplanktongrowth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the ocean’s surface to deeper levels Paragraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbon dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.9.The word “fuels”in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores heatB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More of the Sun’s radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflectedParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. ■However, when deposits of limestone become exposed andweathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. ■What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. ■Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. ■Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares [■] that indicate where the following sentence could be added to the passageNor is carbon dioxide the only gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the air throughlimestone production and photosynthesis or phytoplankton.C.Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming.D.The ocean's capacity to absorb carbon dioxide remains great despite recent reduction of marine plant nutrients such as iron.E.Ocean circulation is strongly controlled by wind and by the sea s balance or salt and heat.F.The ocean bolds and moves a great deal of heat, and as water evaporates, it produces clouds, snow, and ice, which all affect global temperatures.参考答案1-5：DCACB6-10：CBDAC11-13：BAC14：BCF文章来源：雷哥托福倚窗远眺，目光目光尽处必有一座山，那影影绰绰的黛绿色的影，是春天的颜色。

TPO51阅读-3Population Growth in Nineteenth-Century Europe原文 (1)译文 (2)题目 (4)答案 (8)背景知识 (9)原文Population Growth in Nineteenth-Century Europe①Because of industrialization,but also because of a vast increase in agricultural output without which industrialization would have been impossible,Western Europeans by the latter half of the nineteenth century enjoyed higher standards of living and longer,healthier lives than most of the world’s peoples.In Europe as a whole,the population rose from188million in1800to400million in1900.By 1900,virtually every area of Europe had contributed to the tremendous surge of population,but each major region was at a different stage of demographic change.②Improvements in the food supply continued trends that had started in the late seventeenth century.New lands were put under cultivation,while the use of crops of American origin,particularly the potato,continued to expand.Setbacks did occur.Regional agricultural failures were the most common cause of economic recessions until1850,and they could lead to localized famine as well.A major potato blight(disease)in1846-1847led to the deaths of at least one million persons in Ireland and the emigration of another million,and Ireland never recovered the population levels the potato had sustained to that point.Bad grain harvests at the same time led to increased hardship throughout much of Europe.③After1850,however,the expansion of foods more regularly kept pace with population growth,though the poorer classes remained malnourished.Two developments were crucial.First,the application of science and new technology to agriculture increased.Led by German universities,increasing research was devoted to improving seeds,developing chemical fertilizers,and advancing livestock.After 1861,with the development of land-grant universities in the United States that had huge agricultural programs,American crop-production research added to this mix. Mechanization included the use of horse-drawn harvesters and seed drills,many developed initially in the United States.It also included mechanical cream separators and other food-processing devices that improved supply.④The second development involved industrially based transportation.With trains and steam shipping,it became possible to move foods to needy regions withinWestern Europe quickly.Famine(as opposed to malnutrition)became a thing of the past.Many Western European countries,headed by Britain,began also to import increasing amounts of food,not only from Eastern Europe,a traditional source,but also from the Americas,Australia,and New Zealand.Steam shipping, which improved speed and capacity,as well as new procedures for canning and refrigerating foods(particularly after1870),was fundamental to these developments.⑤Europe's population growth included one additional innovation by the nineteenth century:it combined with rapid urbanization.More and more Western Europeans moved from countryside to city,and big cities grew most rapidly of all. By1850,over half of all the people in England lived in cities,a first in human history.In one sense,this pattern seems inevitable growing numbers of people pressed available resources on the land,even when farmwork was combined with a bit of manufacturing,so people crowded into cities seeking work or other resources.Traditionally,however,death rates in cities surpassed those in the countryside by a large margin;cities had maintained population only through steady in-migration.Thus rapid urbanization should have reduced overall population growth,but by the middle of the nineteenth century this was no longer the case.Urban death rates remained high,particularly in the lower-class slums, but they began to decline rapidly.⑥The greater reliability of food supplies was a factor in the decline of urban death rates.Even more important were the gains in urban sanitation,as well as measures such as inspection of housing.Reformers,including enlightened doctors,began to study the causes of high death rates and to urge remediation.Even before the discovery of germs,beliefs that disease spread by"miasmas"(noxious forms of bad air)prompted attention to sewers and open garbage;Edwin Chadwick led an exemplary urban crusade for underground sewers in England in the1830s. Gradually,public health provisions began to cut into customary urban mortality rates.By1900,in some parts of Western Europe life expectancy in the cities began to surpass that of the rural areas.Industrial societies had figured out ways to combine large and growing cities with population growth,a development that would soon spread to other parts of the world.译文十九世纪欧洲的人口增长①由于工业化，也由于农业产量的大幅度增加（如果没有这些就不可能实现工业化），西欧人到了十九世纪后半叶比世界上大多数民族享有更高的生活水平和更长寿，更健康的生活。

为了帮助大家高效备考托福,为大家带来托福TPO51口语Task3阅读文本+听力文本+题目+满分范文,希望对大家备考有所帮助. 托福TPO51口语Task3阅读文本: University Should Build a Parking Lot for the Humanities Building I think the university should consider building a parking lot near the humanities building. Right now there's only street parking available, and it isn't enough. Whenever I look for a spot to park in the street near the humanities building, I can't find one. A parking lot for the humanities building would solve that problem. Also, there's a wooded area behind the building that would make an ideal location for the parking lot. The university could just clear away the trees and build a lot - the space is already there for it. Sincerely, Joe Simmons 托福TPO51口语Task3听力文本: Now, listen to two students discussing the letter. M: Hey, Mary. Did you see this? You think he’s right? W: No. I don’t agree with him. M: How come? W: Well, because it’s not like the street out front is the only space you can park. You can also park at the dining hall, which is only a couple of blocks away or the library, which is a few blocks in the other direction. He doesn’t mention that. M: That’s true. I guess there are other lots nearby. W: Yeah, so there’s not really a need for it. Students may have to walk a little but that’s ok. I don’t think there always needs to be a spot right outside the building you’re going to. M: That’s true. W: But the other problem I have with it is even if they went ahead with his idea, it’s the location he suggests. They can’t just clear away those trees, that’s oneof the only wooded areas left on campus. We don’t have many trees here and they should preserve the ones we have. M: Yeah, it is pretty. W: Well, yeah, and sometimes students like to sit out there in the shade on a nice day to study or read under the trees. They should leave it alone, not destroy it to make away for something we don’t need. 托福TPO51口语Task3题目: The woman expresses her opinion about the letter-writer's proposal. Briefly summarize the proposal. Then state her opinion about the proposal and explain the reasons she gives for holding that opinion. 托福TPO51口语Task3满分范文: In the reading, a student proposes that the school should build a parking lot near the humanities building. The first reason is that students could only park their cars in the street, which is very inconvenient. The second one is that there is a wooded area on campus, which is a perfect site for a parking lot on campus. In the listening, the woman disagrees with the proposal because of two reasons. The first is both the dining hall and library are good places to park and they are not far away from the humanities building. Students may just need to walk a few steps away. The second one is that the wooded area on campus is the only one left for students. It is better for school to leave this place to them where they can study and read books under the shade. 以上是给大家整理的托福TPO51口语Task3阅读文本+听力文本+题目+满分范文,希望对你有所帮助!。

真题：综合写作：solar panels in space的作用（太空利用太阳能）独立写作：Some people think that older children should be required to take care of the younger children. Others think that this should be done by parents or other adults. Which one do you prefer？解析：综合写作：阅读：有很大的优点1. 原因一：可以capture更多的太阳能，因为生产出的太阳能比较多，无云层和大气的遮蔽。

2. 原因二：因为无尘，且陨石撞击可以事先追踪避免，所以不会有撞击。

3. 原因三：对环境好，因为对自然环境的危害比较小。

听力：反驳阅读的三个优点，均不成立。

（住在地球更好）1. 一旦档板坏了不方便维修，出问题的概率很大。

2. 粒子太小了，难以捕捉。

且速度很快的话会产生很多热量，不是很protective.3. 会破坏ozone layer，有很多ultraviolet radiation，对人和动物都会造成很大的危害，所以根本不环保。

独立写作：以下是笔者给出的一个参考答案：choose： older children take care题型：利弊分析类话题：家庭教育类，生活类1. Culturally， older children have been entrusted with the role of the care-taker in a family of more than one child. This is because they are often told to take care of their little brothers or sisters by their parents. Adding that they see their parents in the same way， itis plainly easy for them to identify themselves as parents. For example， girls usually like to tell stories to their younger brothers and sisters， or feed them when their mothers are busy with housework. Boys are like superheroes protecting their flesh and blood from any potential danger. So under certain circumstances， older children are good helpers in nurturing.2. Furthermore， learning to nurture their younger family can help them better prepare for their adult life. Today， many children are spoiled and self-centered. Some of them are even indifferent to others. Consequently， they will have hard time socializing with others in future. In this respect， they are supposed to be taught how to be a responsible citizen. Even though they have very limited abilities in terms of taking care of others， this can make them more responsible and more thoughtful people. So this practice provides them an opportunity to grow up， not only grow old.3. Finally， older children also can enhance family relationship. Many working women have trouble keeping a healthy balance between their family and their work. They often complain about their husbands and have been sick and tired of endless housework and baby-sitting. In this situation， older children can be a good helper in a family， who can reduce their mothers’ workload by doing some small things， making a better family atmosphere. This is definitely a positive way to keepfamily members stay together. Moreover， they will harvest good relationship with their younger brothers and sisters.考试预测1.此次考试题目比较侧重科技，环保类（综合写作），难度稍为有点高，尤其是对于细节的把握稍有难度，并且细节比较密集，词汇也较为生僻，要更加注意对于精听的训练，打好听力硬实力！独立写作比较侧重学习生活中的抉择，是属于近期最常考的话题话题，不是特别难，所以想取得较高的分数需要有一些亮点，无论在语言思路还是素材。

托福TPO51综合写作阅读原文+听力原文+满分范文为了帮助大家高效备考托福，为大家带来托福TPO51综合写作阅读原文+听力原文+满分范文，希望对大家备考有所帮助。

托福TPO51综合写作阅读原文文本：Humans have long been fascinated by elephants, the largest land animal in the modern world. Social animals that live in herds, elephants are native to both Africa and Asia. Their large ears, long trunk, and long life span have made elephants one of the most captivating creatures on Earth. Our long-standing interest in elephants has led to several beliefs about surprising elephant behaviors. Elephants Are Aware of Approaching Death One of the popular beliefs is that when elephants become old and weak, they know that they are nearing the end of their lives. They demonstrate this by breaking away from their herds and going off alone to certain locations often found near bodies of water - so called "elephant graveyards" - to die alone. The idea that old elephants seem aware that they will die soon is supported by the discovery of many sites containing bones exclusively of elderly elephants. Representing Objects through Art Additionally, elephants seem to have artistic ability. Elephants can be taught to hold a paintbrush in their trunk and use it to paint on a canvas. Some elephants have been known to paint drawings that represent recognizable things: flowers, other elephants, even themselves. This talent makes elephants the only animal other than humans to produce art representing the world around them. Fear of Mice Finally, it has long been believed that elephants have a fear of mice. In 77 C.E., the Roman philosopher and scientist Pliny the Elder wrote that elephants are more afraid of mice, small mammals that can do elephants no harm, than of the much moredangerous animals with which elephants normally share an environment, such as lions or tigers. In a recent scientific experiment in which a herd of elephants was confronted with several mice, the elephants backed away from the mice and left the area to avoid them.托福TPO51综合写作听力原文文本：Elephants are fascinating but the beliefs you just read about are based on misunderstandings of elephant behavior.First, we should not assume that old elephants are aware that they will die soon just because they break away from their herds. There is a very practical reason why old elephants leave their herds. You see, when elephants get old enough, their teeth become more down and they have difficulty chewing. So elderly elephants wander away from their herds to look for soft vegetation that’s easier to eat. Soft vegetation is usually found near water. That’s why many old elephants graze near water and eventually die there, an area we’ve come to call “elephant graveyards”.Second, the issue of whether elephants have artistic ability. If you want elephants tra ined to paint, you’ll notice that human trainers stroking the elephants’ears whenever the elephant moves the paintbrush. Elephant ears are very sensitive and touching them in certain ways can be used to train the elephants to do tricks. The trainer teaches the elephant to remember certain patterns of paintbrush strokes and then encourages the elephant to repeat the brushstrokes by touching its ears. So an elephant using a paintbrush is just painting lines it’s been trained to paint. It doesn’t necessarily know that the lines are supposed to represent flowers or animals.Third, Pliny the Elder and others are misinterpreting thereaction of elephants to mice. Elephants that react fearfully to mice aren’t reacting to the mice themselves but to the fact that mice are unfamiliar to them. Being cautious about unfamiliar animals is a natural instinct. But elephants that live in environments where mice are common, like elephants in zoos don’t react with fear to the mice. Clearly, once elephants become familiar with mice and realize that they don’t pose a threat, they don’t mind them.托福TPO51综合写作满分范文：In the reading, the article introduces three surprising beliefs about elephant behaviors. However, in the listening, the professor gives out three reasons why these beli efs can’t stand. First, the reading says that elephants are aware of approaching death. Nevertheless, the listening points out that the true reason why an elephant may break away from the herd is that their teeth become worn out and the animal has to seek for softer plants as their food resources. Therefore, they would get close to the water where soft plants usually occur and finally die there. Second, the reading asserts that elephants have artistic ability and know how to represent objects through art. However, the listening again rejects this statement. According to the lecture, in order to train elephants to paint, the painters will stroke elephant’s ears and help them to memorize certain patterns of paintbrush strokes. In this way, elephant would harness the capacity to draw lines that they are taught to paint. But the thing is that they are just programmed to draw these lines and don’t have any idea of what these lines represent. Third, the reading says that the elephants have a fear of mice. But the listening also disputes this because it supposes the reason why elephants try to avoid mice is that mice are unfamiliar to them not that they are afraid ofthem. Those elephants living in the zoo don’t show any fright of mice because mice are always around them and they get used to these small creatures very much. In another word, once elephants are accustomed to mice, they wouldn’t mind if they are around or not. In a nutshell, by giving all these three reasons, the listening successfully goes against the reading article.以上是给大家整理的托福TPO51综合写作阅读原文+听力原文+满分范文，希望对你有所帮助!。

智课网TOE‎F L备考资料‎新托福阅读经‎典加试题及答‎案：玛雅文明和亚‎历山大帝国摘要：托福加试一般‎分为托福听力‎经典加试，跟托福阅读经‎典加试。

那么托福加试‎算分吗，加试是不算分‎的，但并不意味着‎你可以随便做‎。

下面是新托福‎阅读经典加试‎题及答案：玛雅文明和亚‎历山大帝国。

希望对大家有‎帮助。

新托福阅读经典加试‎题及答案：玛雅文明和亚‎历山大帝国玛雅文明玛雅文明在公‎元前900年‎后的发展, 主要几个re‎g ion原来‎是独立的，后来就有融合‎了，但又不是完全‎融合，有自己的特点‎亚历山大帝国‎覆灭后的发展‎托福阅读经典加试：亚历山大帝国‎覆灭后的发展‎讲述的是亚历‎山大大帝死后‎，他的王国分裂‎为三个，然后又被罗马‎人统治了。

下面，又讲尼罗河埃‎及的发展。

其中的希腊创‎造了一种文明‎。

文章讲述了文‎明的发生和影‎响。

由于涉及到一‎些历史人物和‎地名，单词有点难，不过题目不是‎很困难。

托福阅读考试‎时间一般是6‎0分钟，在托福阅读加‎试的情况下会‎再加40分钟‎，总体考试即1‎00分钟。

小马过河提醒大家‎托福阅读加试‎题的位置不固‎定，考生很难分辨‎哪一道是加试‎题，只能通过日常‎积累来判断。

大家一定要认‎真做每一道题‎目。

以上就是小马‎小编整理的新托福阅读经典加试‎题及答案：玛雅文明和亚‎历山大帝国，希望考生们可‎以认真学习。

如果想了解最‎新托福考试资讯，请关注小马过河托福频道，关于本文有任‎何疑问，都可以和小马‎过河专家联系‎。

相关推荐:新托福阅读经‎典加试题及答‎案：电报新托福阅读经‎典加试题及答‎案：蜜蜂新托福阅读经‎典加试题及答‎案：苏美尔文明相关字搜索：托福阅读经典‎加试。

TPO51托福综合写作真题阅读与听力材料及参考范文【雷哥托福】阅读：Some companies in the United States have developed “wellness”programs that give rewards or incentives to employees for achieving certain health-related goals, such as stopping smoking or losing weight. The rewards and incentives include cash prizes, extra vacation days, or reduction of the employee’s portion of health insurance fees (in the United States, health insurance fees are usually shared between the employer and the employee). Several arguments have been put forward in favor of the incentive programs.First, the awards and incentives are an excellent motivational tool for people to adopt healthy lifestyles. Many people would like to quit smoking or lose weight, but have difficulty getting started. The incentives provide the extra motivation they need. One study suggests that giving people a cash incentive significantly increases their chances of quitting smoking. And in another study, people who got cash incentives were more likely to lose weight than those who did not.Second, the advocates of incentive programs argue that rewarding people who are willing to adopt healthier lifestyles is only being fair. People who exercise, eat healthy diets, and maintain a healthy weight, for example, are less likely to incur medical costs. Such people deserve to pay smaller health insurance fees or get more vacation days.Third, although the wellness incentives cost a lot of money for companies, the incentives save companies money in the long term. Losses in employee productivity due to illness can be very expensive for employers; programs that help prevent health problems are cheap by comparison. For example, incentive programs have been shown to reduce the risk of diabetes and heart disease. The cost of the incentives given by a company to its employees to maintain their health throughprevention programs is much less than the financial losses to a company caused by employees missing work due to illness and hospitalization.听力音频（添加小助手微信号：ybnt110获取）参考范文：In the lecture, the professor is skeptical about the idea of the reading passage that Wellness Programs in United States bring lots of benefits to companies and employees. The professor argues that the program will not work.Firstly, in the reading passage, the programs can become a motivational tool for people to lose weight and quit smoking, bringing much healthier lifestyle. On the contrary, the professor says that it may be an effective way to motivate employees in short term, but it cannot keep for a long period. Research shows that after several years, people are back to their bad habits.Secondly, the professor opposes reading’s idea that employees will be more inclined to take exercises and have wholesome diets through the motivation of the Wellness Programs by stating that the program is not fair for every employee, because cases differ. Some who have to take care of their family or cope with chores do not have enough time to exercise, while some are just genetically fat.Finally, the professor disapproves the reading’s idea that although the program might cost companies a great deal of money at beginning, it saves more compared to the spending for employees’sickness. The professor points out that company might suffer great financial loss in long term, because many employees will not stay in one company forever.来源：雷哥托福。

TPO51听力解析:递进式结构难点解读为了帮助大家备考托福听力，下面小编给大家带来TPO51听力解析:递进式结构难点解读，希望对大家有所帮助!TPO51听力解析:递进式结构难点解读TPO51听力全部都是递进式文章结构，并没有出现我们常见的并列式和对比式的文章。

比如TPO51的Lecture 3，文章讲了美国著名自然学家、插画家Audubon。

文章并没有明显的组织框架，只是分别从：Audubon的艺术风格、科学贡献、和他画作中的一只特别的鸟这三个方面进行讲解。

所以，递进式文章难点在于结构性弱，文章的进度很难把握。

虽然文章结构性很弱，但是递进式文章普遍逻辑性强。

比如：在提到Audubon的艺术风格时候，很自然的过渡到了他的本质----科学家，然后顺其自然的举了一些他作为科学家的例子。

虽然文章最后提到“他画作中的一只特别的鸟”稍显突兀，但整体文章的内在逻辑，还是可以把握的。

托福听力低分原因归纳托福听力低分原因有哪些?一直以来，托福听力部分的成绩都为托福总体成绩拖了后腿，对于中国学生来说，耳和口一直没能够得到释放，英语学习始终是纸上学习，这也导致了学生托福听力成绩普遍低分。

但如果我们能正确认识到托福听力低分都由哪些原因导致，并进行有针对性的练习，托福听力也可以取得很好的成绩。

下面为大家解析一下托福听力低分原因。

托福听力低分原因之一：语音知识不扎实扎实的语音知识是听写慢速英语的基础。

准确地抓住了语音，即使是生词，也不难根据其发音从词典找到答案。

反之，如果语音知识不够，即使是自己会的词也不一定能听懂，更不用说真正碰到生词了。

由于种.种原因，不少人在锻炼托福听力过程中没有得到足够的语音训练，虽然记住了数千个或上万单词和大量语法知识，可以顺利地阅读书面英语文章，但听不懂用词量只有1500余个的慢速英语广播。

托福听力低分原因之二：词汇量不够词写出来认得，而且也能正确地读出来，但由于对词义的理解大狭窄而听不懂。

或者单个的词写出来认得，能正确地读出来，词义也明白，但不明白与其他词合在一起组成词组以后的意思是什么而听不懂。

新托福TPO5阅读原文(一):Minerals and PlantsTPO-5-1：Minerals and PlantsResearch has shown that certain minerals are required by plants for normal growth and development.The soil is the source of these minerals,which are absorbed by the plant with the water from the soil.Even nitrogen,which is a gas in its elemental state,is normally absorbed from the soil as nitrate ions.Some soils are notoriously deficient in micro nutrients and are therefore unable to support most plant life.So-called serpentine soils,for example,are deficient in calcium,and only plants able to tolerate low levels of this mineral can survive.In modern agriculture,mineral depletion of soils is a major concern,since harvesting crops interrupts the recycling of nutrients back to the soil.Mineral deficiencies can often be detected by specific symptoms such as chlorosis(loss of chlorophyll resulting in yellow or white leaf tissue),necrosis (isolated dead patches),anthocyanin formation(development of deep red pigmentation of leaves or stem),stunted growth,and development of woody tissue in an herbaceous plant.Soils are most commonly deficient in nitrogen and phosphorus. Nitrogen-deficient plants exhibit many of the symptoms just described.Leaves develop chlorosis;stems are short and slender,and anthocyanin discoloration occurs on stems,petioles,and lower leaf surfaces.Phosphorus-deficient plants are often stunted,with leaves turning a characteristic dark green,often with the accumulation of anthocyanin.Typically,older leaves are affected first as the phosphorus is mobilized to young growing tissue.Iron deficiency is characterized by chlorosis between veins in young leaves.Much of the research on nutrient deficiencies is based on growing plants hydroponically,that is,in soilless liquid nutrient solutions.This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the plants.Hydroponics has applications beyond basic research,since it facilitates the growing of greenhouse vegetables during winter. Aeroponics,a technique in which plants are suspended and the roots misted with a nutrient solution,is another method for growing plants without soil.While mineral deficiencies can limit the growth of plants,an overabundance of certain minerals can be toxic and can also limit growth.Saline soils,which have high concentrations of sodium chloride and other salts,limit plant growth,and research continues to focus on developing salt-tolerant varieties of agricultural crops.Research has focused on the toxic effects of heavy metals such as lead,cadmium,mercury,and aluminum;however,even copper and zinc,which are essential elements,can become toxic in high concentrations.Although most plants cannot survive in these soils, certain plants have the ability to tolerate high levels of these minerals.Scientists have known for some time that certain plants,called hyperaccumulators,can concentrate minerals at levels a hundredfold or greater thannormal.A survey of known hyperaccumulators identified that75percent of them amassed nickel,cobalt,copper,zinc,manganese,lead,and cadmium are other minerals of choice.Hyperaccumulators run the entire range of the plant world.They may be herbs,shrubs,or trees.Many members of the mustard family,spurge family, legume family,and grass family are top hyperaccumulators.Many are found in tropical and subtropical areas of the world,where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial pathogens.Only recently have investigators considered using these plants to clean up soil and waste sites that have been contaminated by toxic levels of heavy metals–an environmentally friendly approach known as phytoremediation.This scenario begins with the planting of hyperaccumulating species in the target area,such as an abandoned mine or an irrigation pond contaminated by runoff.Toxic minerals would first be absorbed by roots but later relocated to the stem and leaves.A harvest of the shoots would remove the toxic compounds off site to be burned or composted to recover the metal for industrial uses.After several years of cultivation and harvest,the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated soils.For examples,in field trials,the plant alpine pennycress removed zinc and cadmium from soils near a zinc smelter,and Indian mustard,native to Pakistan and India,has been effective in reducing levels of selenium salts by50percent in contaminated soils.译文：TPO-5-1矿物质和植物研究表明，某些矿物质是植物正常生长发育所必需的。

Tpo-51-L31.What does the professor mainly discuss?A. The steps involved in publishing illustrated books in the 1800sB. The influence of Audubon's The Birds of America on science in the 1800sC. The way in which an illustrator's work has both artistic and scientific significanceD. The need for accuracy in scientific illustrations2.According to the professor, what were two steps Audubon took in producing his illustrations? [Click on 2 answers.]A. He studied birds in their natural habitats.B. He tracked birds along their migration paths.C. He closely studied other illustrated books.D. He provided the printer with detailed instructions.3.What does the professor imply about critics of Audubon's art?A. They did not recognize the motivating factor in Audubon's art.B. They did not like the stylistic changes that Audubon developed over time.C. They were disappointed with Audubon's limited scope of subject matter.D. They thought Audubon's use of oils was unsophisticated.4.Why does the professor discuss Audubon's experiments with vultures and banding birds?A. To help students understand the state of scientific knowledge at the timeB. To provide support for his view of Audubon as a naturalistC. To suggest that Audubon was more successful as a scientist than as an illustratorD. To give examples that show the importance of detail in Audubon's illustrations5.What are Audubon's "mystery birds"?A. Bird illustrations created by Audubon that have been lostB. Bird illustrations that do not seem to match any known speciesC. Bird illustrations that were painted in an uncharacteristically careless mannerD. Bird illustrations that Audubon intended to be fanciful rather than realistic6.What does the professor believe is the most likely explanation for Audubon's warbler illustration?A. Audubon forgot small details when he made the illustration.B. Audubon copied the bird from another artist's drawing.C. The bird was the offspring of two different species.D. That particular species of warbler has since gone extinct.Answers :C/AD/A/B/B/CAudubon the Famous IllustratorListen to part of a lecture in an art history class. The professor has been discussing illustrated books.Professor:I want to take a look one particular book to give you an idea about what was involved in publishing illustrated books in the 1800s.The book’s called The Birds of the America and the illustrator was John James Audubon.So,The Birds of the America, four volumes which contained illustrations of nearly every bird in the United States, over 400 birds, all hand-colored, all painted life-sized, the largest birds painted on the largest printing paper available at that time.This required a lot of dedication. And Audubon is best remembered as an incredibly meticulous accurate artist, a very accomplished illustrator of the natural world.And while there were other artists working on the similar project at the same time, Audubon’s book remains the most well-known and successful of its kind. But, let’s talk a bit about Audubon himself first.First of all, Audubon was not a traditional pain ter.And by this I mean that he didn’t work in oils. He preferred to use water color and pastel crayons.And he worked on paper instead of on canvas.The thing is, Audubon considered the illustrations in his book, not the original water colors, to be his finished product.His water colors were merely preparatory studies, most of which were painted while he was observing birds in the wild. These water colors were then sent to his printer who created the final prints for the book. And Audubon was so concerned with accuracy that he often scribbled notes to the printer around the edges of these original water colors.In fact, you might question whether producing a work of art was even Audubon’s goal. Now, when I look at Audubon’s illustrations, I see a work of art. But, it may make more sense to consider Audubon, first and foremost, as a naturalist, as a scientist. See, the early 19th century when Audubon was painting was a time of major scientific inquiry. And an essential way of spreading scientific knowledge was through those illustrated books.Student:So what did Audubon consider himself? An artist or a scientist?Professor:I’m not sure the distinction between the two was all that clear in the 1800s. I think we can accurately state that the driving force in his art was getting the science right. And this was perhaps a point that critics of his art work at that time just didn’t appreciate.Audubon also study birds in ways that didn’t directly inform his art. Ah, you know what bird banding is right? A bird has a band attached to its foot so we can learn about things like migration patterns. Well, the first recorded instance of anyone doing that, it was Audubon. Another example, a common belief of that time was that vultures used their sense of smell to find food. Audu bon didn’t believe that. So, he tested it. He put a large painting of a dead sheep in a field, and sure enough, vultures found it and started pecking at it.Now, Audubon’s work was very accurate, and we know this because we can compare his illustrations to the birds around us. But sometimes it’s not possible to check. There are actually several birds in his book that no one’s ever seen.These are sometimes called Audubon’s mystery birds, because even though he drew them, there is no evidence that they exist in the wild.For someone who’s respected as a naturalist, isn’t it strange to think that he drew some birds that don’t appear to be real? For example, there is an illustration that appears to be a type of warbler, a small bird. It has a white ring around its eyes and white bars on its wings. No one’s ever seen a warbler like this, so some people wonder if Audubon maybe forgot certain details about this bird when he painted it, or that he copied another artist’s work. But considering that Audubon was such a meticulous artist, well, that might be a better answer.Hybridization is something that’s well-known in birds. And it definitely explains the rather unique-looking duck Audubon painted. He himself suggested that maybe it wasn’t an unknown species but a hy brid, born from two different species. Since then, this particular crossing species has actually been recorded, both in the wild and in captivity. So it turns out that Audubon was right. And this duck actually was a hybrid.。

tpo51三篇托福阅读TOEFL原文译文题目答案译文背景知识阅读-1 (2)原文 (2)译文 (5)题目 (7)答案 (16)背景知识 (19)阅读-2 (21)原文 (21)译文 (24)题目 (26)答案 (35)背景知识 (38)阅读-3 (40)原文 (40)译文 (44)题目 (46)答案 (53)背景知识 (56)阅读-1原文Memphis: United Egypt's First Capital①The city of Memphis, located on the Nile near the modern city of Cairo, was founded around 3100 B.C. as the first capital of a recently united Egypt. The choice of Memphis by Egypt's first kings reflects the site's strategic importance. First, and most obvious, the apex of the Nile River delta was a politically opportune location for the state's administrative center, standing between the united lands of Upper and Lower Egypt and offering ready access to both parts of the country. The older predynastic (pre-3100 B.C.) centers of power, This and Hierakonpolis, were too remote from the vast expanse of the delta, which had been incorporated into the unified state. Only a city withineasy reach of both the Nile valley to the south and the more spread out, difficult terrain to the north could provide the necessary political control that the rulers of early dynastic Egypt (roughly 3000-2600 B.C.) required.②The region of Memphis must have also served as an important node for transport and communications, even before the unification of Egypt. The region probably acted as a conduit for much, if not all, of the river-based trade between northern and southern Egypt. Moreover, commodities (such as wine, precious oils, and metals) imported from the Near East by the royal courts of predynastic Upper Egypt would have been channeled through the Memphis region on their way south. In short, therefore, the site of Memphis offered the rulers of the Early Dynastic Period an ideal location for controlling internal trade within their realm, an essential requirement for a state-directed economy that depended on the movement of goods.③Equally important for the national administration was the ability to control communications within Egypt. The Nile provided the easiest and quickest artery of communication and the national capital was, again, ideally located in this respect. Recent geological surveys of the Memphis region have revealed much about its topography in ancient times. It appears that the location of Memphis may have been evenmore advantageous for controlling trade, transport, and communications than was previously appreciated. Surveys and drill cores have shown that the level of the Nile floodplain has steadily risen over the last five millenniums. When the floodplain was much lower, as it would have been in predynastic and early dynastic times, the outwash fans (fan-shaped deposits of sediments) of various wadis (stream-beds or channels that carry water only during rainy periods) would have been much more prominent features on the east bank. The fan associated with the Wadi Hof extended a significant way into the Nile floodplain, forming a constriction in the vicinity of Memphis. The valley may have narrowed at this point to a mere three kilometers, making it the ideal place for controlling river traffic.④Furthermore, the Memphis region seems to have been favorably located for the control not only of river-based trade but also of desert trade routes. The two outwash fans in the area gave access to the extensive wadi systems of the eastern desert. In predynastic times, the Wadi Digla may have served as a trade route between the Memphis region and the Near East, to judge from the unusual concentration of foreign artifacts found in the predynastic settlement of Maadi. Access to, and control of, trade routes between Egypt and the Near East seems to have been a preoccupation of Egypt’s rulers during the period of state formation. The desire to monopolize foreign trade may havebeen one of the primary factors behind the political unification of Egypt. The foundation of the national capital at the junction of an important trade route with the Nile valley is not likely to have been accidental. Moreover, the Wadis Hof and Digla provided the Memphis region with accessible desert pasturage. As was the case with the cities of Hierakonpolis and Elkab, the combination within the same area of both desert pasturage and alluvial arable land (land suitable for growing crops) was a particularly attractive one for early settlement; this combination no doubt contributed to the prosperity of the Memphis region from early predynastic times.译文孟斐斯：统一的埃及的第一个首都①孟斐斯市位于尼罗河上，毗邻现代开罗市，建于公元前3100年左右，是近代统一的埃及的第一个首都。