1、托福（阅读）模拟试卷 8及答案与解析 一、 Sections Three： Reading Comprehension 0 “Life in Our Solar System“ Although we can imagine life based on something other than carbon chemistry, we know of no examples to tell us how such life might arise and survive. We must limit our discussion to life as we know it and the co
2、nditions it requires. The most important requirement is the presence of liquid water, not only as part of the chemical reactions of life, but also as a medium to transport nutrients and wastes within the organism. The water requirement automatically eliminates many worlds in our solar system. The mo
3、on is airless, and although some data suggest ice frozen in the soil at its poles, it has never had liquid water on its surface. In the vacuum of the lunar surface, liquid water would boil away rapidly. Mercury too is airless and cannot have had liquid water on its surface for long periods of time.
4、Venus has some traces of water vapor in its atmosphere, but it is much too hot for liquid water to survive. If there were any lakes or oceans of water on its surface when it was young, they must have evaporated quickly. Even if life began there, no traces would be left now. The inner solar system se
5、ems too hot, and the outer solar system seems too cold. The Jovian planets have deep atmospheres, and at a certain level, they have moderate temperatures where water might condense into liquid droplets. But it seems unlikely that life could begin there. The Jovian planets have no surfaces where ocea
6、ns could nurture the beginning of life, and currents in the atmosphere seem destined to circulate gas and water droplets from regions of moderate temperature to other levels that are much too hot or too cold for life to survive. A few of the satellites of the Jovian planets might have suitable condi
7、tions for life. Jupiters moon Europa seems to have a liquid-water ocean below its icy crust, and minerals dissolved in that water would provide a rich broth of possibilities for chemical evolution. A Nevertheless, Europa is not a promising site to search for life because conditions may not have rema
8、ined stable for the billions of years needed for life to evolve beyond the microscopic stage. B If Jupiters moons interact gravitationally and modify their orbits, Europa may have been frozen solid at some points in history. C Saturns moon Titan has an atmosphere of nitrogen, argon, and methane and
9、may have oceans of liquid methane and ethane on its surface. D The chemistry of life that might crawl or swim on such a world is unknown, but life there may be unlikely because of the temperature. The surface of Titan is a deadly -179C (-290F). Chemical reactions occur slowly or not at all at such l
10、ow temperatures, so the chemical evolution needed to begin life may never have occurred on Titan. Mars is the most likely place for life in our solar system. The evidence, however, is not encouraging. Meteorite ALH84001 was found on the Antarctic ice in 1984. It was probably part of debris ejected i
11、nto space by a large impact on Mars. ALH84001 is important because a team of scientists studied it and announced in 1996 that it contained chemical and physical traces of ancient life on Mars. Scientists were excited too, but being professionally skeptical, they began testing the results immediately
12、. In many cases, the results did not confirm the conclusion that life once existed on Mars. Some chemical contamination from water on Earth has occurred, and some chemicals in the meteorite may have originated without the presence of life. The physical features that look like fossil bacteria may be
13、mineral formations in the rock. Spacecraft now visiting Mars may help us understand the past history of water there and paint a more detailed picture of present conditions. Nevertheless, conclusive evidence may have to wait until a geologist in a space suit can wander the dry streambeds of Mars crac
14、king open rocks and searching for fossils. We are left to conclude that, so far as we know, our solar system is bare of life except for Earth. Consequently, our search for life in the universe takes us to other planetary systems. 1 The word automatically in the passage is closest in meaning to （ A）
15、partially （ B） actually （ C） occasionally （ D） naturally 2 The word it in the passage refers to （ A） ice （ B） soil （ C） moon （ D） solar system 3 Which of the following statements about the water on Venus is true? （ A） The water evaporated because of the high temperatures. （ B） The water became froze
16、n in the polar regions. （ C） Only a little water is left in small lakes on the surface. （ D） Rain does not fall because there is no atmosphere. 4 The word stable in the passage is closest in meaning to （ A） visible （ B） active （ C） constant （ D） strong 5 What can be inferred from the passage about t
17、he Jovian planets? （ A） Some of the Jovian planets may have conditions that could support life. （ B） Jupiter is classified as one of the Jovian planets. （ C） Europa is the largest of the moons that revolve around Jupiter. （ D） The orbits of the Jovian planets have changed over time. 6 According to p
18、aragraph 5, why would life on Titan be improbable? （ A） It does not have an ocean. （ B） It is not a planet. （ C） It is too cold. （ D） It has a low atmosphere. 7 Which of the sentences below best expresses the information in the highlighted statement in the passage? The other choices change the meani
19、ng or leave out important information. （ A） Life on Mars was found as a result of research in many cases. （ B） The evidence did not demonstrate that there was life on Mars in the past. （ C） Many cases of life were concluded in the history of Mars. （ D） The conclusion was that only one instance of li
20、fe on Mars was verified. 8 The word originated in the passage is closest in meaning to （ A） turned （ B） changed （ C） begun （ D） disappeared 9 Why does the author mention the meteorite “ALH84001“ in paragraph 6? （ A） Because it was found in Antarctica about fifty years ago （ B） Because it was evidenc
21、e of a recent impact on Mars （ C） Because scientists thought that it contained evidence of life on Mars （ D） Because the meteorite probably came from Mars a long time ago 10 How will scientists confirm the existence of life on Mars? （ A） By sending unmanned spacecraft to Mars （ B） By looking at foss
22、ils on Mars （ C） By viewing pictures taken of Mars （ D） By studying the present conditions on Mars 11 Which of the following statements most accurately reflects the authors opinion about life in our solar system? （ A） Life is probably limited to planets in the inner solar system. （ B） There is a lar
23、ge body of evidence supporting life on Mars. （ C） There is little probability of life on other planets. （ D） We should explore our solar system for conditions that support life. 12 Look at the four squares that show where the following sentence could be inserted in the passage. Such periods of freez
24、ing would probably prevent life from developing. Where could the sentence best be added? Click on a square to insert the sentence in the passage. 13 An introduction for a short summary of the passage appears below. Complete the summary by selecting the THREE answer choices that mention the most impo
25、rtant points in the passage. Some sentences do not belong in the summary because they express ideas that are not included in the passage or are minor points from the passage. This question is worth 2 points. Current evidence does not support the theory of life in our solar system. - - - Answer Choic
26、es A The meteorite that was discovered in the Antarctic in the 1980s was thought to contain evidence of early life on Mars, but it was later disputed. B The planet that has the greatest probability for life in the past or now is Mars, but more investigation is required to draw conclusions. C Europa
27、has an ocean under the ice on the surface of the moon, which may contain the chemical combinations required for life to evolve. D Although some of the moons that revolve around Saturn and Jupiter have conditions that might support life, the evidence contradicts this possibility. E Other planetary sy
28、stems must have life that is similar to that which has evolved on Earth because of the principles of carbon chemistry. F It is too hot for life on the planets near the Sun in the inner solar system and too cold on the planets most removed from the Sun in the outer solar system. 13 “Layers of Social
29、Class“ Taken together, income, occupation, and education are good measures of peoples social standing. Using a layered model of stratification, most sociologists describe the class system in the United States as divided into several classes: upper, upper middle, middle, lower middle, and lower class
30、. The different classes are arrayed along a continuum with those with the most money, education, and prestige at the top and those with the least at the bottom. In the United States, the upper class owns the major share of corporate and personal wealth; it includes those who have held wealth for gen
31、erations as well as those who have recently become rich. Only a very small proportion of people actually constitute the upper class, but they control vast amounts of wealth and power in the United States. Those in this class exercise enormous control throughout society. Some wealthy individuals can
32、wield as much power as entire nations. Despite social myths to the contrary, the best predictor of future wealth is the family into which you are born. Each year, the business magazine Forbes publishes a list of the 400 wealthiest families and individuals in the country. Of all the wealth represente
33、d on the Forbes 400 list, most is inherited, although since the 1990s, there has been some increase in the number of people on the list with self-created wealth. Those in the upper class with newly acquired wealth are known as the nouveau riche. Luxury vehicles, high-priced real estate, and exclusiv
34、e vacations may mark the lifestyle of the newly rich. However, although they may have vast amounts of money, they are often not accepted into “old rich“ circles. The upper middle class includes those with high incomes and high social prestige. They tend to be well-educated professionals or business
35、executives. Their earnings can be quite high indeed successful business executives can earn millions of dollars a year. It is difficult to estimate exactly how many people fall into this group because of the difficulty of drawing lines between the upper, upper middle, and middle classes. Indeed, the
36、 upper middle class is often thought of as “middle class“ because their lifestyle sets the standard to which many aspire, but this lifestyle is actually unattainable by most. The middle class is hard to define, in part because being “middle class“ is more than just economic position. A very large po
37、rtion of Americans identify themselves as middle class even though they vary widely in lifestyle and in resources at their disposal. But the idea that the United States is an open-class system leads many to think that the majority have a middle-class lifestyle; thus, the middle class becomes the ubi
38、quitous norm even though many who call themselves middle class have a tenuous hold on this class position. The lower middle class includes workers in the skilled trades and low-income bureaucratic workers, many of whom may actually define themselves as middle class. Also known as the working class,
39、this class includes blue-collar workers (those in skilled trades who do manual labor) and many service workers, such as secretaries, hair stylists, food servers, police, and firefighters. Medium to low income, education, and occupational prestige define the lower middle class relative to the class g
40、roups above it. The term lower in this class designation refers to the relative position of the group in the stratification system, but it has a pejorative sound to many people, especially to people who are members of this class, many of whom think of themselves as middle class. The lower class is c
41、omposed primarily of the displaced and poor. People in this class have little formal education and are often unemployed or working in minimum-wage jobs. A People of color and women make up a disproportionate part of this class. The poor include the working poor those who work at least 27 hours a wee
42、k but whose wages fall below the federal poverty level. Six percent of all working people now live below the poverty line. The concept of the underclass has been added to the lower class. B The underclass includes those who are likely to be permanently unemployed and without means of economic suppor
43、t. C Rejected from the economic system, those in the underclass may become dependent on public assistance or illegal activities. D 14 The word those in the passage refers to （ A） characteristics （ B） groups （ C） classes （ D） continuum 15 The word enormous in the passage is closest in meaning to （ A）
44、 very large （ B） very new （ C） very early （ D） very good 16 Which of the sentences below best expresses the information in the highlighted statement in the passage? The other choices change the meaning or leave out important information. （ A） Although it is not generally accepted, your family provid
45、es the best prediction of your future wealth. （ B） You can achieve great future wealth in spite of the family in which you may have been born. （ C） It is not true that your family will restrict the acquisition of your future wealth and level of social status. （ D） Social myths are contrary to the fa
46、cts about the future wealth and social status of your family. 17 Why does the author mention the “Forbes 400“ in paragraph 3? （ A） To explain the meaning of the listing that appears every year （ B） To support the statement that most wealthy people inherit their money （ C） To cast doubt on the claim
47、that family income predicts individual wealth （ D） To give examples of successful people who have modest family connections 18 The word exclusive in the passage is closest in meaning to （ A） long （ B） expensive （ C） frequent （ D） relaxing 19 In paragraph 4, the author states that business and profes
48、sional people with educational advantages are most often members of the （ A） lower middle class （ B） upper middle class （ C） nouveau riche （ D） upper class 20 According to paragraph 5, why do most people identify themselves as middle class in the United States? （ A） They have about the same lifestyl
49、e as everyone else in the country. （ B） They prefer not to admit that there are class distinctions in the United States. （ C） They dont really know how to define their status because it is unclear. （ D） They identify themselves with the majority who have normal lifestyles. 21 The word primarily in the passage is closest in meaning to （ A） mostly （ B） somewhat （ C） finally （ D） always 22 What can be inferred about the working class in the United States? （ A） They are often not able to find entry-level jobs. （ B） They work in jobs that pay minimum wage. （ C） They are ser
