托福TPO15阅读Passage2原文文本+题目+答案解析

雅思剑桥15text2阅读The IELTS Cambridge 15 Text 2 Reading passage is titled "The effects of light on plant and animal species." This passage discusses the impact of artificial light on various organisms and ecosystems. It explores how light pollution affects plants, animals, and humans, and provides insights into the measures that can be taken to mitigate these effects.The passage begins by explaining that artificial light at night disrupts the natural light-dark cycle that organisms have evolved to rely on. This disruption can have detrimental effects on both plants and animals. For example, excessive light can interfere with the growth and development of plants, leading to reduced crop yields and changes in plant behavior. It can also disrupt the behavior and reproductive patterns of animals, affecting their feeding habits, migration, and mating rituals.Furthermore, light pollution can have indirect effects on ecosystems. For instance, it can alter the behavior of nocturnal animals, making them more vulnerable to predation or causing them to abandon their habitats. This disruption can have cascading effects on the entire food chain, impacting other species that depend on these nocturnal animals for food or other ecological services.In addition to its impact on plants and animals, artificial light at night can also affect human health. The passage highlights that exposure to bright light at night can disrupt the production of melatonin, a hormone that regulates sleep-wake cycles. This disruption can lead to sleep disorders, such as insomnia, and increase the risk of various health problems, including obesity, diabetes, and certain types of cancer.To mitigate the negative effects of light pollution, the passage suggests several measures that can be taken. These include using outdoor lighting fixtures that direct light downward and minimize light spillage, implementing lighting curfews or dimming lights during certain hours, and creating designated dark sky areas where artificial light is limited. These measures aim to reduce the amount of artificial light that escapes into the environment and minimize its impact on organisms and ecosystems.In conclusion, the IELTS Cambridge 15 Text 2 Reading passage discusses the effects of artificial light on plant and animal species. It highlights the negative consequences of light pollution on plants, animals, and human health. The passage also suggests various measures that can be taken to mitigate these effects, emphasizing the importance of responsible outdoor lighting practices and the creation of dark sky areas. By understanding and addressing the impacts of light pollution, we can strive to protect and preserve the natural light-dark cycles that are essential for the well-being of all organisms.。

Q1正确答案：C解析：以mass extinctions做关键词定位至第一句，提到大量生物在短时间内灭绝的这种现象叫做大灭绝事件，C是原文的同义替换，所以是正确答案。

70 million 和250 million是两次大灭绝事件发生的时间，不是A说的七千万年一直在发生，也不是D说的每2500万年发生一次；B的began和原文的end是相反的，错误。

Q2正确答案：A解析：定位到第二段的最后两句：如今物种灭绝的比率和之前五次大规模物种灭绝时期一样高。

因此许多科学家推断，目前正处于第六次大规模物种灭绝状态。

选A。

Q3正确答案：D解析：extend“延伸，延长”，extended“长期的”，所以long是正确答案。

原句说其他机制可能会渐渐发生，在一个什么样的时期内，既然是渐渐发生，当然需要比较长的时间，所以答案是D。

虽然长但不是无限，所以unlimited错误；specific “特定”时间和reasonable“合理”时间原文都没提到。

Q4正确答案：C解析：EXCEPT题，本段第一句就问了原因第二句就开始回答，所以这道题正选比较好。

第二句的warming or cooling对应D答案，正确，不选；changing positions of the continents对应B答案，正确，不选；最后一句的habitat destruction对应A 答案，正确，不选；只有C没有对应，所以C错误，可选。

Q5正确答案：D解析：提问全段的，最好用排除法。

A的exact causes做关键词定位至第三段前两句，原文提到有很多假设，所以没有准确原因，A错误；B的future原文没提到，所以错误；C的一大堆生物做关键词定位至第三句，但原文没提它们是最先遭殃的一群生物，C错误；D的land and seas做关键词定位至倒数第三句，simultaneously就是at the same time，正确。

Q6正确答案：A解析：原文主干部分讲的是：这两个人认为物种大规模灭绝是呈周期出现的，补充信息有：（1）这两个人曾经从大量化石群中研究物种灭绝的比率；（2）从白垩纪中期后差不多每2600万年出现一次大规划物种灭绝。

为了帮助大家高效备考托福，为大家带来托福TPO15听力Conversation2文本+题目+答案解析，希望对大家备考有所帮助。

托福TPO15听力Conversation2文本 Narrator: Listen to part of a conversation between a student and her biology professor. Professor: Hi, Samantha, how did your track meet go? Student: Great! I placed first in one race and third in another. Professor: Congratulations, you must practice a lot. Student: Three times a week pre-season, but now that we are competing every weekend. We practice six days a week from 3:30 to 5. Professor: Athletics places a heavy demand on your time, don’t they? Student: Yeah, but I really love competing, so… Professor: You know, I played soccer in college and my biggest challenge, and I didn’t always succeed, was getting my studying in during soccer season. Are you having a similar? Student: No. I really do make time to study, and I actually study more for this class than I do for all my other classes. But I didn’t see the grade I expected on my mid-term exam which is why I came by. Professor: Well, you didn’t do badly on the exam but I agree it did not reflect your potential. I say this because your work on the lab project was exemplary. I was so impressed with the way you handled the microscope and the samples of onion cells and, well, how careful you observed and diagramed and interpreted each stage of cell division, and I don’t think you could have done that if you hadn’t understood the chapter. I mean, it seemed you really had a good understanding of it. Student: I thought so, too. But I missed some questions about cell division on the exam. Professor: So, what happened? Student: I just sort of blanked out, I guess. I had a hard time remembering details. It was so frustrating. Professor: All right. Let’s back up. You say you studied. Where? At home? Student: At my kitchen table, actually. Professor: And that’s supposed to be a quiet environment? Student: Not exactly. My brother and parents try to keep it down when I’m studying but the phone pretty much rings off the hook, so. Professor: So you might try a place with fewer distractions, like, the library. Student: But the library closes at midnight and I like to study all night before a test. You know, so everything is fresh in my mind. I studied six straight hours the night before the mid-term exam. That’s why I expected to do so much better. Professor: Oh, OK. You know that studying six consecutive hours is not equivalent to studying one hour a day for six days. Student: It isn’t? Professor: No, there’s a research that shows that after an hour of intensive focus, your brain needs a break. It needs to, you know, shift gears a little. Your brain’s ability to absorb information starts to decline after about the first hour. So if you are dealing with a lot of new concepts and vocabulary, anyway, if you just review your notes even twenty minutes a day, it’d be much better than waiting until the night before the exam to try and absorb all those details. Student: Oh, I didn’t realize. Professor: Think of your brain as a muscle. If you didn’t practice regularly with your track team, and then try to squeeze in three weeks’ worth of running practice the day before a track meet, how well do you think you will perform in the races? 托福TPO15听力Conversation2题目 1.Why does the woman go to see her professor? A. To tell him about an athletic achievement. B. To find out the best approach to studying for a test. C. To ask a question about a laboratory project.。

托福考试 复习托福阅读TPO15(试题+答案+译文)第2篇:Mass Extinctions物种灭绝托福阅读原文【1】Cases in which many species become extinct within a geologically short interval of time are called mass extinctions. There was one such event at the end of the Cretaceous period(around 70 million years ago). There was another, even larger, mass extinction at the end of the Permian period (around 250 million years ago). The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.【2】The fossil record shows at least five mass extinctions in which many families of marine organisms died out. The rates of extinction happening today are as great as the rates during these mass extinctions. Many scientists have therefore concluded that a sixth great mass extinction is currently in progress.【3】What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposedmechanisms required a very brief period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fail to account for simultaneous extinctions on land and in the seas. Each mass extinction may have had a different cause.Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction.【4】American paleontologists David Raup and John Sepkoski, who have studied extinction rates in a number of fossil groups, suggest that episodes of increased extinction have recurred periodically, approximately every 26 million years since the mid-Cretaceous period. The late Cretaceous extinction of the dinosaurs and ammonoids was just one of the more drastic in a whole series of such recurrent extinction episodes. The possibility that mass extinctions may recur periodically has given rise to such hypotheses as that of a companion star with along-period orbit deflecting other bodies from their normal orbits, making some of them fall to Earth as meteors and causing widespread devastation upon impact.【5】Of the various hypotheses attempting to account for the late Cretaceous extinctions, the one that has attracted the most attention in recent years is the asteroid-impact hypothesis first suggested by Luis andWalter Alvarez. According to this hypothesis, Earth collided with an asteroid with an estimated diameter of 10kilometers, or with several asteroids, the combined mass of which was comparable. The force of collision spewed large amounts of debris into the atmosphere, darkening the skies for several years before the finer particles settled. The reduced level of photosynthesis led to a massive decline in plant life of all kinds, and this caused massive starvation first of herbivores and subsequently of carnivores. The mass extinction would have occurred very suddenly under this hypothesis.【6】One interesting test of the Alvarez hypothesis is based on the presence of the rare-earth element iridium (Ir).Earth’s crust contains very little of this element, but most asteroids contain a lot more. Debris thrown into the atmosphere by an asteroid collision would presumably contain large amounts of iridium, and atmospheric currents would carry this material all over the globe. A search of sedimentary deposits that span the boundary between the Cretaceous and Tertiary periods shows that there is a dramatic increase in the abundance of iridium briefly and precisely at this boundary. This iridiumanomaly offers strong support for the Alvarez hypothesis even though no asteroid itself has ever been recovered.【7】An asteroid of this size would be expected to leave an immense crater, even if the asteroid itself was disintegrated by the impact. The intenseheat of the impact would produce heat-shocked quartz in many types of rock. Also, large blocks thrown aside by the impact would form secondary craters surrounding the main crater.To date, several such secondary craters have been found along Mexico’s Yucatan Peninsula, and heat-shocked quartz has been found both in Mexico and in Haiti.A location called Chicxulub, along the Yucatan coast, has been suggested as the primary impact site.托福阅读试题1.Paragraph 1 supports which of the following statements about mass extinctions?A.They take place over a period of 70 million years.B.They began during the Cretaceous period.C.They eliminate many animal species that exist at the time they occur.D.They occur every 250 million years.2.According to paragraph 2, scientists base their belief that a mass extinction is going on at present on which of the following?A.The speed with which mass extinctions are happening today is similar to the speed of past extinctions.B.The number of species that have died out since the last extinction event is extremely large.C.Mass extinctions occur with regularity and it is time for another one.D.Fossil records of many marine species have disappeared.3.The word extended in the passage is closest in meaning toA.specific.B. unlimited.C.reasonable.D. long.4.According to paragraph 3, each of the following has been proposed asa possible cause of mass extinctions EXCEPTA.habitat destruction.B.continental movement.C.fierce interspecies competition.D.changes in Earth's temperature.5.Paragraph 3 supports which of the following ideas about mass extinctions?A.Scientists know the exact causes of most mass extinctions.B.Mass extinctions are unlikely to happen again in the future.C.Insects, flowering plants, and bottom-feeding predators in the oceans tend to be the first organisms to disappear during episodes of mass extinctions.D.Some mass extinctions occurred on land and in the seas at the same time.6.Which of the sentences below best expresses the essential information in the underlined sentence （Paragraph 4）in the passage? Incorrect choices change the meaning in important ways or leave out essential information.A.Based on their studies of extinction rates of numerous fossil groups, paleontologists David Raup and John Sepkoski have determined that mass extinctions occur about every 26 million years.B.David Raup and John Sepkoski studied extinction rates of numerous fossil groups and suggest that mass extinctions during the Cretaceous period continued for 26 million years.C.Studies that paleontologists David Raup and John Sepkoski conducted of various fossil groups have revealed that extinction rates have increased over the past 26 million years.D.The studies conducted by paleontologists David Raup and John Sepkoski of the fossil remains of species suggest that the extinction rate of species started to increase by the middle of the Cretaceous period. 7.According to paragraph 4, what aspect of extinction episodes does the companion-star hypothesis supposedly clarify?A.Their location.B.Their frequency.C.Their duration.D.Their severity.8.The phrase account for in the passage(Paragraph 5)is closest in meaning toA.describe.B.challenge.C.explain.D.test.9.According to paragraph 6, what made iridium a useful test of the Alvarez hypothesis?A.Its occurrence in a few locations on Earth against several locations on other planets.B.Its occurrence in limited quantities on Earth against its abundance in asteroids.C.Its ability to remain solid at extremely high temperatures.D.Its ease of detection even in very small amounts.10.In stating that no asteroid itself has ever been recovered, the author emphasizes which of the following?A.The importance of the indirect evidence for a large asteroid.B.The fact that no evidence supports the asteroid impact hypothesis.C.The reason many researchers reject the Alvarez hypothesis.D.The responsibility of scientists for not making the effort to discover the asteroid itself.11.The word intense（Paragraph 7）in the passage is closest in meaningtoA.sudden.B.unusual.C.immediate.D. extreme.12.What is the purpose of paragraph 7 in the passage?A.It proposes a decisive new test of the Alvarez hypothesis.B.It presents additional supporting evidence for the Alvarez hypothesis.C.It explains why evidence relating to the Alvarez hypothesis is hard to find.D.It shows how recent evidence has raised doubts about the Alvarez hypothesis.13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? In general, it is believed that these two extinctions resulted from drastic environmental changes that followed meteorite impacts or massive volcanic eruptions.■Cases in which many species become extinct within a geologically short interval of time are called mass extinctions. ■There was one such event at the end of the Cretaceous period (around 70 million years ago). ■There was another, even larger, mass extinction at the end of the Permian period (around 250 million years ago). ■The Permian event has attracted muchless attention than other mass extinctions because mostly unfamiliar species perished at that time.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.There have been many attempts to explain the causes of mass extinctions.A.Asteroid impacts, evolutionary developments, and changes in Earth's climate and in the positions of the continents have all been proposed as possible causes of mass extinctions.B.Researchers have observed 26-million-year cycles in extinction rates of a number of fossil groups that could all be attributed to the same cause.C.According to the Alvarez hypothesis, much of the iridium originally present on Earth was thrown into the atmosphere as a result of an asteroid impact that also caused a mass extinction.D.The unusual distribution of iridium on Earth and the presence of craters and heat-shocked quartz are central to the theory that an asteroid impact caused the late Cretaceous event.E.The collision between Earth and a large asteroid resulted in massive damage and generated enough heat to cause irreversible changes inEarth's atmosphere.F.There was a particularly large mass extinction that occurred around 250 million years ago at the end of the Permian period, whose cause could not be determined.托福阅读答案1.以mass extinctions做关键词定位至第一句，说大量生物在短时间内灭绝的这种现象叫做大灭绝事件，C是原文的同义替换，所以是正确答案。

托福阅读答案1.interlock连锁，连接，所以B的link正确。

从单词本身看，inter表示在……之间，lock表示锁，所以这个词应该是锁在什么什么中间的意思，所以link靠谱，frozen只表示锁，没有之间，所以不对；而intermediate只表示在……之间，没有固定的意思，所以不对；fully develop完全不对2.EXCEPT题，排除法。

A的hexagonal crystal做关键词定位至第二句，但原文没说形成thick layer，A错，选；B的compact和grain做关键词同样定位至第二句，正确，不选；C的granules做关键词定位至倒数第三句，正确，不选；D的air space做关键词定位至第三句，正确，不选3.match匹配，所以equal是答案。

原句说冰川如果想保持其体积不变或者增大，必须有足够的降雪量来怎么样或者超过融化已经其他过程造成的损失，肯定是先说弥补上，再说超过，所以equal相等，相当正确。

measure 完全不对；approximate接近不行，因为只是接近的话没法保持冰川体积不变；enlarge和exceed意思一样，不选4.transform形变，变形，所以C的change正确。

从单词本身看，trans表示转移，转换，form形式，所以整个单词应该是变形之意。

原句说降雪量超过融化的量剩余的那些雪经过若干年后能形成必要把雪怎么成冰川的压力，当然是变成冰川，所以change正确5.EXCEPT题，排除法。

A的pressure做关键词定位至倒数第二句，正确，不选；B的三个动名词和做关键词定位至第二句，正确，不选；C的firn做关键词定位至前一段的倒数第三句，正确，不选；D的两种glaciers做关键词定位至最后一句，两者是并列关系，没有谁比谁怎么样，所以D错，选6.以fast moving glaciers做关键词定位至最后一句，说冰川可以按温度分为快速移动的temperate和慢速移动的polar，所以要快速移动就必须得是temperate，所以A和C说反，D压根儿没提气候的事儿，所以正确答案是B7.deceive欺骗，所以deceiving欺骗性的，所以D的misleading正确。

TPO 15 阅读分析A Warm-Blooded T urtle单词篇cellular metabolism 细胞新陈代谢长难句篇In a countercurrent exchange system, the blood vessels carrying cooled blood from the flippers run close enough to the blood vessels carrying warm blood from the body to pick up some heat from the warmer blood vessels; thus, the heat is transferred from the outgoing to the ingoing vessels before，it reaches the flipper itself.在逆流交换循环系统中，血管将冷却的血液从鳍部带来与血管从身体它处带来的温热的血液进行交换。

因此在到达鳍部前，热量通过流进的血液和流出的血液完成了热量转移。

句子分析：句子出现一对平行结构，由run close enough 连接。

后半句内容和前面构成因果关系。

学习句型篇1.When it comes to physiology, the leatherback turtle is, in some ways, more like a reptilian whale than a turtle.当谈及到生理学时，棱皮龟在某些方面上更像一个爬行类的鲸鱼。

题目分析篇1.What can be inferred about whales from paragraph 1?○They are considered by so me to be reptiles.○Their bodies are built in a way that helps them manage extremely cold temp eratures○They are distantly related to leatherback turtles.○They can swim farther than leatherback turtles.【推断题】定位句：It swims farther into the cold of the northern and southern oceans than any other sea turtle（不是leatherback turtles 所以4错误）, and it deals with the chilly waters in a way unique among reptiles.（与2吻合）2.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.○In a turtle's countercurrent exchange system, outgoing vessels lie near enough to ingoing ones that heat can b e exchanged from the former to the latter before reaching the turtle' s flippers.○Within the turtle' s flippers, there is a countercurrent exchange system that allows colder blood vessels to absorb heat from nearby warmer blood vessels and then return warmed blood to the turtle's body. 没有提到吸收不吸收的问题○In a countercurrent exchange system, a turtle can pi ck up body heat f rom being close enough to other turtles, thus raising its blood temperature as it passes them.红字部分错误是自己完成了转移而不是靠其他的turtles○When a turtle places its flippers close to its body,it is able to use its countercurrent exchange system to transfer heat from the warmer blood vessels in its body to the cooler blood vessels in its flippers逻辑关系错误，是从cold to warm 而不是warm to cold【句子分析题】3.Paragraph 3: Leatherbacks keep their body heat in three different ways. The first, and simplest, is size. The bigger the animal is, the lower as surfaceto-volum e ratio; for every ounce of body mass, there is proportionately less surface through whi ch heat can escape. An adult leatherback is twice the size of the biggest cheloniid sea turtles and will therefore take longer to cool off. Maintaining a high body temperature through sheer bulk is called gigantotherrny. █ It works for elephants, for whales, and, perhaps, it worked for many of the larger dinosaurs. █ It apparently works, in a smaller way, for some other sea turtles. █ Large loggerhead and green turtles can maintain their body temperature at a degree or two abovethat of the surrounding water, and gigantothermy is probably the way they do a. █ Muscular activity helps, too, and an actively swimming green turtle may be T C (12.6° F) warmer thanthe waters it swims through.3.Look at the four squares [█] that indicate where the following sentence could be added to the passage.However, these animals have additional means of staying warm. 3 4Where would the sentence best fit?【插入题】插入的句子含有these animal s 的指代词，所以插入的上句必须要有these animals 本段结构：讲明保持身体体温的三个不同方法，然后分别讲述，加入的句子含义为：然而，这些动物还有别的方法来保持体温。

为了帮助大家高效备考托福，为大家带来托福TPO2阅读Passage2原文文本+题目+答案解析，希望对大家备考有所帮助。

▉托福TPO2阅读Passage2原文文本： The Origins of Cetaceans It should be obvious that cetaceans-whales, porpoises, and dolphins-are mammals. They breathe through lungs, not through gills, and give birth to live young. Their streamlined bodies, the absence of hind legs, and the presence of a fluke and blowhole cannot disguise their affinities with land dwelling mammals. However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like. Extinct but already fully marine cetaceans are known from the fossil record. How was the gap between a walking mammal and a swimming whale bridged? Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans. Very exciting discoveries have finally allowed scientists to reconstruct the most likely origins of cetaceans. In 1979, a team looking for fossils in northern Pakistan found what proved to be the oldest fossil whale. The fossil was officially named Pakicetus in honor of the country where the discovery was made. Pakicetus was found embedded in rocks formed from river deposits that were 52 million years old. The river that formed these deposits was actually not far from an ancient ocean known as the Tethys Sea. The fossil consists of a complete skull of an archaeocyte, an extinct group of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans. The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales. Pakicetus probably detected sound through the ear opening as in land mammals. The skull also lacks a blowhole, another cetacean adaptation for diving. Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh- eating mammals, the mesonychids, and cetaceans. It has been suggested that Pakicetus fed on fish in shallow water and was not yet adapted for life in the open ocean. It probably bred and gave birth on land. Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-longBasilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs. An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetus natans ("the walking whale that swam") lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea. The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea. ▉托福TPO2阅读Passage2题目： Question 1 of 13 In paragraph 1, what does the author say about the presence of a blowhole in cetaceans? 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.. Question 2 of 13 Which of the following can be inferred from paragraph 1 about early sea otters? A. It is not difficult to imagine what they looked like.. B. There were great numbers of them.. C. They lived in the sea only.. D. They did not leave many fossil remains.. uestion 3 of 13。

托福阅读真题第151篇TwoKindsofLizards（答案文章最后）Two Kinds of LizardsParagraph 1：Lizards can be divided into two types according to the way they look for food: sit-and-wait foragers and active foragers. Sit-and-wait lizards normally remain in one spot from which they can survey a broad area. These motionless lizards detect the movement of an insect visually and capture it with a quick run from their observation site. Sit-and-wait lizards may be most successful in detecting and capturing relatively large insects like beetles and grasshoppers. Active foragers, on the other hand, spend most of their time on the ground surface, moving steadily and poking their heads under fallen leaves and into crevices in the ground. These lizards apparently rely largely on chemical cues to detect insects, and they probably seek out local concentrations of prey such as termites. Active foragers appear to eat more insects than do lizards that are sit-and-wait predators. Thus, the different foraging behaviors of lizards lead to differences in their diets, even when the two kinds of lizards occur in the same habitat.1. According to paragraph 1, sit-and-wait foragers and active foragers are different in all of the following EXCEPTO the methods that they primarily use to detect insectsO the number of insects they typically eatO the habitats in which they can be foundO the amount of time they spend moving2. According to paragraph 1, compared to the insects typically consumed by sit-and-wait lizards, insects typically consumed by active lizardsO move more quicklyO are generally found in smaller groupsO are often hidden from viewO spend more time on the surface of the groundParagraph 2：The different foraging modes also have different consequences for lizards regarding their exposure to predators. A lizard that spends 99 percent of its time resting motionless is relatively inconspicuous, whereas a lizard that spends most of its time moving is easily seen. Sit-and-wait lizards are probably most likely to be discovered and captured by predators that are active searchers, whereas widely foraging lizards are likely to be caught by sit-and-wait predators. Because of this difference, foraging modes may alternate at successive levels in the food chain: insects that move about may be captured by lizards that are sit-and-wait foragers, and those lizards may be eaten by active predators, whereas insects that are sedentary are more likely to be discovered by lizards that are active foragers, and those lizards may be caught by sit-and-wait predators.3. In paragraph 2, why does the author contrast the visibility of lizards that remain motionless most of the time with the visibility of lizards that move most of the time？O To show that it is possible for lizards to alternate their foraging modes at successive levels in the food chain O To suggest that sit-and-wait lizards are more likely than active lizards to be attacked by predatorsO To explain why sit-and-wait lizards are more successful than active lizards at preying on insectsO To explain how a lizard's foraging strategy affects the type of predator likely to attack itParagraph 3：The body forms of sit-and-wait foragers mayreflect selective pressures different from those that act on active foragers. Sit-and-wait lizards are often stout bodied, short tailed, and colored to match their background. Many of these species have patterns of different-colored blotches that probably obscure the outlines of the lizard's body as it rests motionless on a rock or a tree trunk. Active foragers are usually slim and elongated with long tails, and they often have patterns of stripes that may produce optical illusions as they move. However, one predator-avoidance mechanism, the ability to break off their tails when they are seized by predators, does not differ among lizards with different foraging modes.4. Paragraph 3 supports which of the following ideas about active-forager lizards？O They are less likely to break off their tails when seized by predators than sit-and-wait lizards are.O They tend to vary widely in their individual colors.O They lack well-developed mechanisms for avoiding predators.O They may be easier to identify when they are not moving than when they are moving.Paragraph 4：What physiological characteristics are necessary to support different foraging modes? The energy requirements of a quick motion that lasts for only a second or two are quite different from those of locomotion that is sustained nearly continuously for several hours. Sit-and-wait lizards and active foragers differ in their relative emphasis on the two ways that most animals use adenosine triphosphate (ATP), a molecule that transports energy within cells for activity, and in how long that activity can be sustained. Sit-and-wait lizards move in brief spurts, and they rely largely on anaerobic metabolism to sustaintheir movements, namely the kind of metabolism that does not use oxygen. Anaerobic metabolism uses glycogen stored in the muscles and produces lactic acid as its end product. It is a way to synthesize ATP quickly (because the glycogen is already in the muscles), but it is not good for sustained activity because the glycogen is quickly exhausted and lactic acid inhibits cellular metabolism. Lizards that rely on anaerobic metabolism can make brief sprints but become exhausted when they are forced to run continuously. In contrast, aerobic metabolism uses glucose that is carried to the muscles by the circulatory system, and it produces carbon dioxide and water as end products. Aerobic exercise can continue for long periods because the circulatory system brings more glucose and carries carbon dioxide away. As a result, active foragers can sustain activity for long periods without exhaustion. Active species of lizards have larger hearts and more red blood cells in their blood than do sit-and-wait species. As a result, each beat of the heart pumps more blood, and that blood carries more oxygen to the tissues of an active species than a sit-and-wait species.5. According to paragraph 4, compared with active lizards, the movements of sit-and-wait lizards areO more suddenO more sustainedO more predictableO more frequent6. According to paragraph 4, all of the following are true about anaerobic metabolism in lizards EXCEPT:O It uses the glycogen in the muscles of lizards.O It produces lactic acid that interferes with metabolism within the cells of lizards.O It allows lizards to maintain their foraging activity over a long period of time.O It allows lizards to run fast for short periods of time.7. Which of the following can be inferred from paragraph 4 about sit-and-wait lizards？O They have less glycogen than active-forager lizards.O They have highly variable heart rates.O They have metabolic systems that do not depend on the efficient removal of carbon dioxide.O They synthesize adenosine triphosphate continuously.8. According to paragraph 4, how are active-foraging lizards and sit-and-wait lizards different from each other？O Sit-and-wait lizards tend to have more red blood cells in their blood than active-foraging lizards do.O Active-foraging lizards' blood carries less oxygen to the tissues than sit-and-wait foraging lizards' blood does.O Sit-and-wait lizards carry out cellular metabolism more efficiently than active-foraging lizards do.O Active-foraging lizards tend to have larger hearts than sit-and-wait lizards do.Paragraph 3：The body forms of sit-and-wait foragers may reflect selective pressures different from those that act on active foragers. Sit-and-wait lizards are often stout bodied, short tailed, and colored to match their background. ■Many of these species have patterns of different-colored blotches that probably obscure the outlines of the lizard's body as it rests motionless on a rock or a tree trunk. ■Active foragers are usually slim and elongated with long tails, and they often have patterns of stripes that may produ ce optical illusions as they move. ■However, one predator-avoidance mechanism, the ability to break off their tailswhen they are seized by predators, does not differ among lizards with different foraging modes.■9. Look at the four squares that indicate where the following sentence could be added to the passage.Such visual effects make it harder for predators to catch these moving targets.Where would the sentence best fit? Click on a square to add the sentence to the passage.10. 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 express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Drag your choices to the spaces where they belong. To review the passage, click on View Text.Answer ChoicesO Sit-and-wait lizards use brief spurts of energy to forage, while the movements of active lizards are more sustained.O Lizards that are active foragers are able to detect insects even when those insects are stationary, but sit-and-wait lizards are able to detect only moving insects.O Sit-and-wait lizards tend to have predators that are active, while active lizards tend to have sit-and-wait predators.O Sit-and-wait lizards have less need for bodies that match their environment than active lizards do because of the ease with which they can break off their tails to escape from predators.O The body forms and metabolic functions of the two types of lizards differ in ways that support the requirements of their different foraging behaviors.O Sit-and-wait lizards derive energy for movement from anaerobic metabolism alone, while active lizards rely almost equally on aerobic and anaerobic metabolisms.。

TPO15 listening 问题解析注：问题中红色标记词汇为解题突破点和关键词。

（编辑整理by Astra）Section 1TPO15-L1 Conversation 11. Why does the student go to the campus newspaper office?O To turn in outlines of possible articlesO To find out when his article will be printed in the newspaperO To find out if he got a position as a reporterO To get help with an assignment for his journalism class答案：C解析：男学生报名做reporter，写好的outline一周前已经提交，但是没有收到答复，他来看一下情况。

原文如下：I sent them in about a week ago, but I haven't heard anything back yet, so, so I thought I'd stop by and see, but I guess you haven't looked at them yet2. Why does the student want to write for the campus newspaper?O He wants to earn some money.O He wants to learn about the newspaper business.O He wants to share his enthusiasm for physics.O He thinks the experience will be valuable.答案：D解析：男学生知道当reporter是没有报酬的，但是这有利于他写个人经历，比较重要。

第15套Thermal StratificationParagraph1Physical characteristics of aquatic environments at different depths such as salt level, light,inorganic nutrients,degree of acidity,and pressure all play key roles in the distribution of organisms.One of the most important physical features is thermal stratification.Paragraph2When solar radiation strikes water,some is reflected,but most penetrates the surface and is ultimately absorbed.Although water may appear transparent,it is much denser than air and absorbs radiation rapidn clear water,99percent of the solar radiation is absorbed in the upper50to100meters.Longer wavelengths of light are absorbed first; the shorter wavelengths(which have more energy)penetrate farther,giving the depths their characteristic blue color.1.The word ultimately in the passage is closest in meaning toA.probablyB.quicklyC.eventuallyD.frequently2.According to paragraph2,which of the following is true about solar radiationwhen it strikes waterA.Longer wavelengths travel farther.B.Most of it is absorbed near the surface.C.It is not absorbed by cloudy water.D.More long wavelengths than short wavelengths are absorbed.Paragraph3This rapid absorption of sunlight by water has two important consequences.First,it means that photosynthesis the process by which plants use the energy of sunlight to produce the organic carbon compounds necessary for life can only occur in surface waters where the light intensity is sufficiently high.Species that produce their own organic carbon compounds are called primary producers,and they are the base of the marine food web.Virtually all of the photosynthesis that supports the rich life of oceans and lakes comes from plants living in the upper10to30meters of water. Along shores and in very shallow bodies of water,some species such as kelp are rooted to the bottom.These plants may attain considerable size and structural complexity,and may support diverse communities of organisms.In the open waters that cover much of the globe,however,the primary producers of organic carbon are tiny,often one-celled algae(called phytoplankton),which are suspended in the water.Zooplankton,tiny invertebrates that feed on phytoplankton,migrate vertically on a daily cycle:up into the surface waters at night to feed and down into the dark,deeper waters during the day to escape predatory fish that rely on light to detect prey.3.The word virtually in the passage is closest in meaning toA.ApparentlyuallyC.NearlyD.Fortunately4.According to paragraph3,all of the following are true of kelp EXCEPT:A.They are found at the bottom of shallow waters.B.They are the primary producers of organic carbon.C.They can grow very large.D.They are a source of food for a variety of organisms.5.The word suspended in the passage is closest in meaning toA.dissolvedB.floatingC.invisibleD.released6.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.Zooplankton move up into surface waters at night to feed on phytoplankton,and down into deep,dark waters in daytime to avoid detection by predatory fish.B.Zooplankton migrate vertically on a daily basis in order to feed on phytoplankton, following them up into surface waters by day and down into dark,deeper waters at night.C.Unlike zooplankton,which migrate between surface waters and deeper waters, predatory fish must rely on the daytime light of surface waters to detect prey.D.Zooplankton are so tiny that they can only be detected by predatory fish in the light conditions of surface water,where they feed on phytoplankton.Paragraph4Second,the rapid absorption of sunlight by water means that only surface water is heated.The density of pure water is greatest at4degrees and declines as the water's temperature rises above or falls below this point.When solar radiation heats the water surface above4¡ãC,the warm surface water becomes lighter than the cool,deeper water,and so tends to remain on the surface,where it may be heated further and become even less dense.In tropical areas and in temperate climates during the summer,the surfaces of oceans and lakes are usually covered by a thin layer of warmwater.Unless these bodies of water are shallow,the deep water below this layer is much colder(sometimes near4degrees).The change in temperature between the warm surface water and the cold,deep water is called the thermocline.Mixing of the surface water by wave action determines the depth of the thermocline and maintains relatively constant temperatures in the water above it.7.According to paragraph4,what is a thermoclineA.The deep,cold layer of water below the surface of oceans and lakesB.The thin layer of warm water on the surface of oceans and lakesC.The change in density of surface water as it is continually heatedD.The point at which the temperature of water in oceans and lakes changes from warm to coldParagraph5Tropical lakes and oceans show pronounced permanent stratification of their physical properties,with warm,well-oxygenated,and lighted surface water giving way to frigid,dark,deep water almost devoid of oxygen.Oxygen cannot be replenished at great depths where there are no photosynthetic organisms to produce it,and the stable thermal stratification prevents mixing and reoxygenation by surface water.Only relatively few organisms can live in such extreme conditions.The waste products and dead bodies of organisms living in the surface waters sink to the depths,taking their mineral nutrients with them.The lack of vertical circulation thus limits the supply of nutrients to the phytoplankton above.Consequently,deep tropical lakes are often relatively unproductive and depend on continued input from streams for the nutrients required to support life.8.The word replenished in the passage is closest in meaning toA.absorbedB.restoredC.containedD.obtained9.According to paragraph5,all of the following are true of the water at great depths in tropical lakes EXCEPT:A.It has less oxygen than the surface water does.B.It is very dark.C.It contains relatively few living organisms.D.It has low levels of mineral nutrients.Paragraph6The situation is somewhat different in temperate and polar waters.Deep lakes,in particular,undergo dramatic seasonal changes:they develop warm surface temperatures and a pronounced thermocline in summer,but freeze over in winter. Twice each year,in spring and fall,the entire water column attains equal temperatureand equal density;moderate winds may then generate waves that mix deep and shallow water,producing what is called overturn.This semiannual mixing carries oxygen downward and returns inorganic nutrients to the surface.Phosphorus and other nutrients may be depleted during the summer;overturn replenishes these nutrients by stimulating the growth of phytoplankton.10.The word dramatic in the passage is closest in meaning toA.partialplexC.frequentD.striking11.According to paragraph6,after overturn,deep water levels of lakes in temperate climates will contain increased amounts ofA.warm waterB.phosphorusC.oxygenD.phytoplankton12.According to paragraphs5and6,temperate lakes are in general more productive than tropical lakes becauseA.temperate lakes receive more nutrients from incoming streamsB.the summer thermocline is relatively deep in temperate lakesC.solar radiation penetrates more of the water in temperate lakesD.temperate lakes experience vertical circulation of waterParagraph2When solar radiation strikes water,some is reflected,but most penetrates the surface and is ultimately absorbed.[A]Although water may appear transparent,it is much denser than air and absorbs radiation rapidly.[B]In clear water,99percent of the solar radiation is absorbed in the upper50to100meters.[C]Longer wavelengths of light are absorbed first;the shorter wavelengths(which have more energy)penetrate farther,giving the depths their characteristic blue color.[D]13.Look at the four squares that indicate where the following sentence could be added to the passage.If the water is clouded by many microscopic organisms,absorption occurs even closer to the surface.Where would the sentence best fit?Click on a square to add the sentence to the passage.14.Drag your choices to the spaces where they belong.To review the passage,click on View Text.Answer ChoicesA.Sunlight is rapidly absorbed by the upper layer of water,which makes it warmer and consequently less dense than the water below.B.Photosynthesizing plants,which provide the food and oxygen for most other forms of aquatic life,are limited to the levels of oceans and lakes where sunlight is available.C.The diversity of plant life in shallow water makes it attractive to zooplankton.D.As water becomes less dense and moves to the surface of the ocean or lake,it cools down and moderates the temperature of the surface.E.Because more solar energy is absorbed by bodies of water in the tropics,the topmost layer of the thermocline is widest there.F.In the tropics,permanent thermal stratification limits the amount of life supported in deep bodies of water;however,in temperate climates,seasonal thermal stratification allows vertical circulation and mixing of water,allowing the support of more life.Live PerformanceParagraph1Unlike video and cinema(although sometimes employing elements of both),the theater is a living,real-time event,with both performers and audience mutually interacting,each aware of the other's immediate presence.This turns out to be an extremely important distinction.Distinguished film stars,particularly those with theater backgrounds(as most have),routinely return to the live dramatic stage despite the substantially greater financial rewards of film work and invariably prefer stage acting because of the immediate audience response theater provides,with its corresponding sensations of excitement and presence.1.The word distinction in the passage is closest in meaning toA.ideaB.blendC.definitionD.difference2.Paragraph1makes which of the following points about theater and filmA.Theater audiences tend to be more critical than film audiences.B.Actors in the theater are usually not as well-known as film actors.C.Theater companies tend to pay more than film companies do for the most distinguished actors.D.Audiences respond to actors differently in theater than in film.3.Paragraph1suggests that the reason distinguished film stars return to live theater is that theyA.are able to command higher fees as well-known actorsB.enjoy the excitement of performing before a live audienceC.have great respect for theatrical drama as an art formD.are dissatisfied with the roles they are offered in films and television Paragraph2The first of these is the rapport existing between actor and audience.[A]Both are breathing the same air;both are involved at the same time and in the same space with the stage life depicted by the play.[B]Sometimes their mutual fascination is almost palpable;every actor's performance is affected by the way the audience yields or withholds its responses:its laughter,sighs,applause,gasps,silences.[C]Live theatrical performance is always a two-way communication between stage and house.[D]4.The word rapport in the passage is closest in meaning toA.excitementB.balanceC.bondD.fascinationParagraph3Second,theater creates a relationship among the audience members.Having arrived at the theaters as individuals or in groups of two or three,the audience members quickly find themselves fused into a common experience with total strangers:laughing at the same jokes,empathizing with the same characters,experiencing the same revelations. This broad communal response is never developed by television drama,which is played chiefly to solitary or clustered viewers who(because of frequent commercial advertisements)are only intermittently engaged,nor is it likely to happen in movie houses,where audience members essentially assume a one-on-one relationship with the screen and rarely(except in private or group screenings)break out in a powerful collective response,much less applause.By contrast,live theatrical presentations generate audience activity that is broadly social in nature:the crowd arrives at the theater at about the same time,people mingle and chat during intermissions,and all depart together,often in spirited conversation about the play.Moreover,they communicate during the play:laughter and applause build upon themselves and gain strength from the recognition that others are laughing and applauding.The final ovation unique to live performance inevitably involves the audience applauding itself, as well as the performers,for understanding and appreciating the theatrical excellence they have all seen together.And plays with political themes can even generate collective political response.In a celebrated example,1935s Waiting for Lefty was staged as if the audience were a group of union members;by the play's end the audience was yelling Strike!Strike!in response to the play's issues.Obviously,only a live performance could evoke such a response.5.In paragraph3,which of the following is mentioned as support for the statementthat This broad communal response is never developed by television dramaA.Television drama is rarely about serious social issues.B.People do not usually talk to each other while watching television.C.Television audiences vary greatly in their interest in television dramas.D.People do not typically watch television in large groups.6.According to paragraph3,movie house audiences are different from audiences at live theatrical performances because movie house audiences do notA.enjoy humor and jokes as much as theater audiences doB.develop broad communal responsesC.sympathize with the characters they see dramatizedD.generally applaud unless everyone else is applauding7.Why does the author mention the play Waiting for LeftyA.To illustrate the power of the communal response to playsB.To argue that plays about political subjects have more power to evoke deepfeelings in an audience than nonpolitical plays doC.To provide an example of a play that was a popular success because it dealt withimportant political issuesD.To compare the political importance of plays in recent times with the politicalimportance of earlier playsParagraph4Finally,live performance inevitably has the quality of immediacy.The action of the play is taking place right now,as it is being watched,and anything can happen. Although in most professional productions the changes that occur in performance from one night to another are so subtle that only an expert would notice,the fact is that each night's presentation is unique,and everyone present the audience,the cast, and those behind the scenes knows it.This awareness lends an excitement that cannot be achieved by theatrical events that are wholly in the can.One reason for the excitement,of course,is that in live performance,mistakes can happen;this possibility occasions a certain abiding tension,perhaps even an edge of stage fright, which some people say creates the ultimate thrill of the theater.But just as disaster can come without warning,so too can splendor.On any given night,each actor is trying to better his or her previous performance,and no one knows when this collective effort will coalesce into something sublime.The actors'constant striving toward self-transcendence gives the theater a vitality that is missing from performances fixed unalterably on videotape or celluloid.But perhaps most appropriately,the immediacy of live performance embodies the fundamental uncertainty of life.One prime function of theater is to address the uncertainties of human existence,and the very format of live performance presents a moment-to-moment uncertainty right before our eyes.Ultimately,this immediate theater helps us define the questions and confusions of our lives and lets us grapple,in the present,with their implications.8.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.Although experts can detect the changes that occur in different performances,the changes are too subtle to be noticed by anyone else.B.Although their performances vary only subtly from one night to another,actors in most professional productions want audiences to believe that every performance is unique.C.Everyone involved in the professional production of a play knows that very small, almost unnoticeable changes make each performance unique.D.In most professional productions,changes are included from one performance to another that are intended to make every performance a unique one.9.The word thrill in the passage is closest in meaning toA.goalB.weaknessC.meaningD.excitement10.The word vitality in the passage is closest in meaning toA.styleB.energyC.purposeD.quality11.According to paragraph4,on any given night the result of actors'efforts to better their previous performances is that the actorsA.form long-lasting relationships with the audienceB.are better able to overcome their stage frightC.create a quality that is not present in film or televisionD.are more likely to be admired by audiences12.It can be inferred from paragraph4that one of the reasons filmed performances are less exciting than live theatrical performances is becauseA.there is little chance that a mistake will occur in a filmed performanceB.most movies portray situations that audiences have seen beforeC.audiences are interested in seeing famous actors live rather than on a screenD.most people are accustomed to going to the movies but view the theater as a special event13.Look at the four squares that indicate where the following sentence could be added to the passage.Such signs of an audience's engagement thus become part of every performance.Where would the sentence best fit?Click on a square to add the sentence to the passage.The first of these is the rapport existing between actor and audience.[A]Both are breathing the same air;both are involved at the same time and in the same space with the stage life depicted by the play.[B]Sometimes their mutual fascination is almost palpable;every actor's performance is affected by the way the audience yields or withholds its responses:its laughter,sighs,applause,gasps,silences.[C]Live theatrical performance is always a two-way communication between stage and house.[D]14.Drag your choices to the spaces where they belong.To review the passage,click on View Text.Answer ChoicesA.Although live theater is unlike either video or cinema,the different genressometimes overlap.B.While live theater is regarded by most film actors as the most exciting place toperform,many are too troubled by stage fright to perform live.C.In the theater,there is a two-way communication between actor and audience thathas an effect on the actor's performance.D.Audiences at live theatrical performances form a special connection,sharing thecommon experience of reacting to a live theatrical performance.E.Many people go to the theater excited to see in a live performance an actor thatthey have never seen before except on television or in films.F.The excitement of live theater cannot be achieved in any other medium,and itsimmediacy and uncertainty help us deal with life's fundamental uncertainty.Earthquake Prediction（此篇17年3月25日考到了）Paragraph1Accurate prediction of earthquakes is not currently possible,although intensive research is proceeding in many areas.Paragraph2Two types of earthquake prediction are theoretically possible.The first type is long-term forecasting,in which the probability of an earthquake along a particular segment of a within a certain time interval is calculated by studying seismic gaps and historical records of earthquakes that have occurred along that fault segment.By plotting the number of earthquakes within specific time intervals against their magnitudes,diagrams can be constructed for a local area.From this plot it is possible to determine the recurrence interval,or the average time interval between earthquakes of a specific magnitude.Predictions can then be made that an earthquake of thatmagnitude has a high probability of occurrence within a specified time interval,if the date of the last earthquake is known.1.The word specified in the passage is closest in meaning toA.probableB.statedC.shortD.typical2.According to paragraph2,all of the following information is used in the process of long-term earthquake prediction EXCEPT theA.analysis of seismic gapsB.record of past earthquakes in the fault areaC.date of the last recorded earthquake in the areaD.pattern of earthquake activity in other nearby fault segments3.According to paragraph2,long-term forecasting can be used to predict which of the followingA.The influence of earthquake activity in one segment of the fault area on othersegmentsB.The frequency with which earthquakes of a certain size will occurC.The possible date of the next earthquakeD.The magnitude of the next earthquakeParagraph3Research leading to short-term forecasting,which involves a shorter time interval,has been focused on precursors observed prior to previous earthquakes.Precursors are physical or chemical phenomena that occur in a typical pattern before an earthquake. These phenomena include changes in the velocity of seismic waves,the electrical resistance of rocks,the frequency of the usually minor preliminary earthquakes (foreshocks),the deformation of the land surface,and the water level or water chemistry of wells in the area.Many of these precursors can be explained by a theory called the dilatancy model.Under this hypothesis,rocks in the process of strain along a fault show significant dilation or swelling before rupture.This volume increase is caused by the opening of microcracks,which are minute failure zones in weaker mineral grains in the rock and along grain boundaries.Groundwater flows into the highly stressed areas during the formation of microcracks.These changes in density and water content affect the ability of the rock to transmit seismic waves and conduct electricity.Therefore,seismic-wave velocity and electrical resistance progressively change as the overall rupture along the fault draws near.Localized changes in land-surface elevation are also related to volume changes at depth.An area of recent uplift along the San Andreas Fault near Los Angeles,which has been named the Palmdale Bulge,is being monitored in great detail as a possible indicator of a future earthquake.4.The word focused in the passage is closest in meaning toA.dependentB.fundedC.concentratedD.published5.Paragraph3mentions all of the following as examples of precursors EXCEPTA.changes in the speed of seismic wavesB.changes in the availability of electricityC.changes in the frequency of foreshocksD.changes in land surfaces6.According to the dilatancy model,what happens to rocks shortly before an earthquakeA.They lose significant amounts of moisture.B.They show signs of expanding.C.They move downward at great speed.D.They increase in temperature.7.According to paragraph3,the groundwater that flows into microcracks before an earthquake causesA.changes in seismic waves and electrical activityB.increases in the mineral content of rocksC.the disappearance of grain boundaries in rocksD.a release in the tension of highly stressed areas of rocks8.The author discusses the San Andreas Fault near Los Angeles in order toA.contrast past and future patterns of earthquake activity in the areaB.give an example of an area where underground earthquake activity is apparentfrom land changes above the groundC.explain why recent earthquake predictions have increased accuracyD.suggest that some areas of earthquake activity are easier to monitor than others Paragraph4Volume changes and groundwater movement may be reflected by changes in water levels in wells and also by changes in the chemical composition of groundwater. Radon gas has been observed to increase in wells prior to earthquakes.These increases are perhaps related to the release of radon gas from rocks during the formation of microcracks.The pattern of seismic activity is also significant in the vicinity of a fault area where rupture is imminent.This pattern consists of an initial rise in the number of small events,followed by a decline in foreshocks just prior to the major earthquake.The decline may represent a temporary increase in rock strength before the newly formed microcracks are filled with water.9.According to paragraph4,which of the following occurs just before an earthquakeA.The chemical content of groundwater drops.B.The rocks weaken as they fill with water.C.Seismic activity decreases.D.Radon gas causes microcracks to form.10.The word imminent in the passage is closest in meaning toA.frequentB.well understoodC.known to occurD.about to happenParagraph5The precursor phenomena can be grouped into stages according to the dilatancy model.Stage I consists of a gradual stress buildup along the fault.Stages II and III are correlated with dilatancy and water influx.Stage IV is the major earthquake,and stage V is the aftermath of the event.[A]If every earthquake followed the sequence with uniform stage duration,earthquake prediction would be a simple matter.[B]Instead of following the same patterns,each earthquake is unique in terms of specific precursor behavior patterns and length of precursor stages.[C]A magnitude6.9North American earthquake in1989was preceded by a substantially smaller magnitude5 earthquake fifteen months before the event.[D]Another foreshock of similar size occurred two months before the event.In each case,a public advisory was issued stating that those smaller earthquakes could be foreshocks to a stronger earthquake within five days.However,the fault did not cooperate,and those predictions were not successful.Continued research and study of future earthquakes will certainly lead to refinement of the dilatancy model or to a replacement model with more accurate predictive capabilities.11.How is paragraph5organizedA.The sequence of earthquake stages is given,and the effect of variable stage lengthon earthquake prediction is explained.B.The earthquake stages are named,and the most important stage is illustrated with aspecific earthquake event.C.The sequence of earthquake stages is given,and evidence is presented that theintervals between stages are roughly equal in length.D.The earthquake stages are first named,and each is then described in greater detail.12.The word refinement in the passage is closest in meaning toA.reconsiderationB.acceptanceC.improvementD.extension13.Look at the four squares that indicate where the following sentence could be added to the passage.But the reality of earthquake forecasting is considerably more complex. Where would the sentence best fit?Click on a square to add the sentence to the passage.The precursor phenomena can be grouped into stages according to the dilatancy model.Stage I consists of a gradual stress buildup along the fault.Stages II and III are correlated with dilatancy and water influx.Stage IV is the major earthquake,and stage V is the aftermath of the event.[A]If every earthquake followed the sequence with uniform stage duration,earthquake prediction would be a simple matter.[B]Instead of following the same patterns,each earthquake is unique in terms of specific precursor behavior patterns and length of precursor stages.[C]A magnitude6.9North American earthquake in1989was preceded by a substantially smaller magnitude5 earthquake fifteen months before the event.[D]Another foreshock of similar size occurred two months before the event.In each case,a public advisory was issued stating that those smaller earthquakes could be foreshocks to a stronger earthquake within five days.However,the fault did not cooperate,and those predictions were not successful.Continued research and study of future earthquakes will certainly lead to refinement of the dilatancy model or to a replacement model with more accurate predictive capabilities.14.Drag your choices to the spaces where they belong.To review the passage,click on View Text.Answer ChoicesShort-term forecasting has been used more widely than long-term forecasting in the prediction of earthquakes.B.Long-term forecasting of earthquakes uses data on past seismic activity to determine the likelihood that an earthquake will occur in a certain area within a certain time period.C.Short-term forecasting research has studied earthquake precursors such as volume increases in rocks and unusual movements in underground water that occur shortly before an earthquake takes place.D.The dilatancy model has been used to successfully forecast some recent earthquakes.E.Attempts to improve forecasting by using five stages of earthquake predictors have been unsuccessful because each earthquake has unique precursor patterns and durations.F.The magnitude6.9North American earthquake in1989was not successfully predicted because the many foreshocks before the event were too small to measure.Thermal Stratification。