1、大学英语四级改革适用（阅读）模拟试卷 52及答案与解析 Section C 0 Imagine an animal that becomes frozen in cold weather. Then, when it gets warmer, the animal simply unfreezes and goes back to its normal life. Although this may sound like something from a science-fiction movie, it is exactly what happens to the wood frog ove
2、r winter and spring. When winter begins, the frog, which is found throughout much of Canada, buries itself in leaves and dirt. As the ground begins to freeze, so does the frog s body. Normally, if a living creature is frozen, the cells inside its body are destroyed, leading to death. How, then, does
3、 the wood frog survive? The secret lies in the fact that although the water between the cells in the frog s body becomes frozen, the water inside the cells does not freeze. Before the winter begins, the frog stores starch in its body. As the weather gets colder, the drop in temperature causes the fr
4、og s body to change this starch into glucose. This glucose, in turn, lowers the temperature at which the liquid inside the frogs cells freezes. As a result, the cells do not freeze even at very low temperatures, allowing the frog to stay alive. Some wood frogs stay in this frozen state with their he
5、arts stopped completely for months without harm. Now researchers are hoping to adapt the wood frog s secret to help them preserve human organs for transplants. Currently, after organs are removed from a donor s body, they are packed in a special liquid and kept very cold. However, they cannot be fro
6、zen because the ice would damage the cells in the organs. For this reason, the organs must be used quickly. If doctors had a way to preserve organs longer, they would have more time to find the best matches among people waiting for organ transplants. There is still a lot about the wood frog that sci
7、entists do not understand. They still have to work out, for example, exactly how the frog is able to unfreeze itself and what actually restarts the frogs heart when the weather becomes warmer. What is clear, however, is that lessons learned by studying this tiny creature could be of great benefit to
8、 humans in the near future. 1 The wood frog is unusual because it_. （ A） can move about easily on frozen ground （ B） buries itself in leaves and dirt at the start of spring （ C） survives even after its body has become frozen （ D） lives a normal life even in very cold weather 2 What effect does the g
9、lucose produced in the wood frog s body have? （ A） It stops the water in the frog s cells from freezing in cold weather. （ B） It lowers the temperature in the spaces between the frog s cells. （ C） It causes the frog s cells to produce more starch. （ D） It allows the frog s cells to produce more wate
10、r. 3 Researchers are hoping to use the wood frog s secret to allow them to_. （ A） use transplant organs more quickly （ B） remove organs from a donor more easily （ C） unfreeze transplant organs with chemicals from the frogs （ D） keep transplant organs longer than they can now 4 Which is one thing tha
11、t scientists would like to find out about the wood frog? （ A） Whether it becomes frozen in the spring. （ B） How its heart starts again when it unfreezes. （ C） Which parts of its body freeze in cold weather. （ D） Why it takes so long to unfreeze at the end of winter. 5 Which of the following is true?
12、 （ A） The wood frog needs starch in order to stop the cells in its body from dying. （ B） Researchers are trying to find a way to transplant the organs of wood frogs. （ C） Wood frogs use the glucose in their cells to unfreeze their bodies at the end of winter. （ D） Scientists are now using the proces
13、s that takes place in a wood frogs body to prepare human organs for transplant. 5 Since ancient times, the destructive effects of earthquakes on human lives and property have encouraged the search for reliable methods of earthquake prediction. This challenge remains and modern scientists continue to
14、 search for reliable methods to determine the time, place and intensity of individual quakes. One prediction technique involves an analysis of the recurrence(重现 )rates of earthquakes as indicators of future activity. Earthquakes are concentrated in certain areas of the world which are subject to con
15、stant movements of earth s plates and it is in these areas that scientists focus their investigations. This search for pre-earthquake phenomena has received particular attention. In contrast to the ancient Greeks and Romans, who relied on the crying of dogs as a warning sign, modern scientists have
16、focused on physical evidence for a coming earthquake. Evidence of plate strain can be found by measuring relative movements, while chemical changes also offer signals for scientists. Analysis of the changes in magnetic properties and conductivity(传导性 )of rocks provides further data for prediction. T
17、he electrical and magnetic properties of crustal(地壳的 )rocks are particularly sensitive to strain. The conductivity of crustal rock is determined by the degree to which the rock is soaked with fluid and the electrolytic properties of those fluids. Before large earthquakes, small fractures develop in
18、rocks, which change the quantity of fluid present. These changes can be measured and provide useful data. However, similar changes in the fluid, bearing capacity of rock can occur as a result of other factors such as changes in the water table, and therefore this technique is not entirely reliable.
19、The ancient believe that the behavior of birds, cats and dogs provides evidence of inevitable earthquakes has recently been attended as a result of tests carried out in California. It has been shown that changes taking place in the metabolic(新陈代谢的 )rates of these animals correlate with subsequent se
20、ismic activity. It is assumed that the animals are sensitive to the seismic waves which precede major quakes. In zones where earthquakes are known to occur, improved construction techniques can significantly reduce the effects of seismic waves. If more accurate information regarding the time and int
21、ensity were available, governments could take even more effective measures to reduce the impact on human life, if, however, an entirely accurate prediction technique became available, there would be significant social and political implications. 6 Recurrence rates of earthquakes can help predict fut
22、ure quakes because_. （ A） improvement in mathematics allows figures to be more accurate （ B） this method has been used since ancient times and proved very effective （ C） most scientists focus their investigations on the quakes of certain areas （ D） continuous plate movements often result in earthqua
23、kes in certain areas 7 Which of the following is used by modern scientists to indicate a coming earthquake? （ A） The crying of dogs. （ B） The conductivity of rocks. （ C） The changes in the water table. （ D） The quantity of fluid in earth. 8 Crustal rocks can be used to predict earthquakes for their_
24、. （ A） conductivity of electricity （ B） sensitivity to strain （ C） hardness to be cracked （ D） magnetic properties 9 A disadvantage of fluid measuring is that_. （ A） changes in quantity of fluid in rocks can be caused by other factors other than strain （ B） present scientific instruments are not abl
25、e to provide precise measurement （ C） the electrical properties of the rock itself also change the fluid capacity of rocks （ D） fractures in these rocks are often so serious that accurate measurement is impossible 10 It can be inferred from the passage that_. （ A） animals can be used as very accurat
26、e indications of earthquakes （ B） coming earthquakes can be precisely predicted now （ C） construction improvements can help diminish destructive effects of earthquakes （ D） ancient people are wiser than modern men in using animals for earthquake predictions 10 Is language, like food, a basic human n
27、eed without which a child at a critical period of life can be starved and damaged? Judging from the drastic experiment of Frederick in the thirteenth century, it may be. Hoping to discover what language a child would speak if he heard no mother tongue, he told the nurses to keep silent. All the infa
28、nts died before the first year. But clearly there was more than lack of language here. What was missing was good mothering. Without good mothering, in the first year of life especially, the capacity to survive is seriously affected. Today no such severe lack exists as that ordered by Frederick. Neve
29、rtheless, some children are still backward in speaking. Most often the reason for this is that the mother is insensitive to the signals of the infant, whose brain is programmed to learn language rapidly. If these sensitive periods are neglected, the ideal time for acquiring skills passes and they mi
30、ght never be learned so easily again. A bird learns to sing and to fly rapidly at right time, but the process is slow and hard once the critical stage has passed. Experts suggest that speech stages are reached in a fixed sequence and at a constant age, but there are cases where speech has started la
31、te in a child who eventually turns out to be of high IQ. At twelve weeks a baby smiles and utters vowel-like sounds; at twelve months he can speak simple words and understand simple commands; at eighteen months he has a vocabulary of three to fifty words. At three he knows about 1,000 words which he
32、 can put into sentences, and at four his language differs from that of his parents in style rather than grammar. Recent evidence suggests that an infant is born with the capacity to speak. What is special about man s brain, compared with that of the monkey, is the complex system which enables a chil
33、d to connect the sight and feel of, say, a teddy-bear with the sound pattern “teddy-bear“. And even more incredible is the young brain s ability to pick out an order in language from the mixture of sound around him, to analyze, to combine and recombine the parts of a language in new ways. But speech
34、 has to be induced, and this depends on interaction between the mother and the child, where the mother recognizes the signals in the child s babbling, grasping and smiling, and responds to them. Insensitivity of the mother to these signals dulls the interaction because the child gets discouraged and
35、 sends out only the obvious signals. Sensitivity to the child s non-verbal signals is essential to the growth and development of language. 11 The purpose of Fredericks experiment was_. （ A） to prove that children are born with ability to speak （ B） to discover what language a child would speak witho
36、ut hearing any human speak （ C） to find out what role careful nursing would play in teaching a child to speak （ D） to prove that a child could be damaged without learning a language 12 The reason that some children are backward in speaking is most likely that_. （ A） they are incapable of learning la
37、nguage rapidly （ B） they are exposed to too much language at once （ C） their mothers respond inadequately to their attempts to speak （ D） their mothers are not intelligent enough to help them 13 What is particularly remarkable about a child is that_. （ A） he is born with the capacity to speak （ B） h
38、e has a brain more complex than an animal s （ C） he can produce his own sentences （ D） he owes his speech ability to good nursing 14 Which of the following is NOT implied in the passage? （ A） The faculty of speech is inborn in man. （ B） The child s brain is highly selective. （ C） Most children learn
39、 their language in definite stages. （ D） Children do not need to be encouraged to speak. 15 If a child starts to speak later than others, he will_in future. （ A） have a high IQ （ B） be less intelligent （ C） be insensitive to verbal signals （ D） not necessarily be backward 15 One of the most contenti
40、ous issues in the vast literature about alcohol consumption has been the consistent finding that those who don t drink tend to die sooner than those who do. The standard Alcoholics Anonymous(匿名戒酒互助会 )explanation for this finding is that many of those who show up as abstainers(戒酒者 )in such research a
41、re actually former hard-core drunks who had already incurred health problems associated with drinking. But a new paper in the journal Alcoholism: Clinical and Experimental Research suggests that for reasons that arent entirely clear abstaining from alcohol does tend to increase one s risk of dying,
42、even when you exclude former problem drinkers. The most shocking part is abstainers mortality rates are higher than those of heavy drinkers. Moderate drinking, which is defined as one to three drinks per day, is associated with the lowest mortality rates in alcohol studies. Moderate alcohol use(espe
43、cially when the beverage of choice is red wine)is thought to improve heart health. But why would abstaining from alcohol lead to a shorter life? Its true that those who abstain from alcohol tend to be from lower socioeconomic classes, since drinking can be expensive. And people of lower socioeconomi
44、c status have more life stressors job and child-care worries that might not only keep them from the bottle but also cause stress-related illness over long periods.(They also dont get the stress-reducing benefits of a drink or two after work.) But even after controlling for nearly all imaginable vari
45、ables socioeconomic status, level of physical activity, number of close friends, quality of social support and so onthe researchers(a six-member team led by psychologist Charles Holahan of the University of Texas at Austin)found that over a 20-year period, mortality rates were highest for those who
46、were not current drinkers, regardless of whether they used to be alcoholics, second highest for heavy drinkers and lowest for moderate drinkers. 16 What s the Alcoholics Anonymous attitude towards the findings? （ A） Negative. （ B） Positive. （ C） Supportive. （ D） Neutral. 17 What do we know from the
47、new paper in the journal Alcoholism: Clinical and Experimental Research? （ A） Abstaining from alcohol can lead to a happier life. （ B） The mortality rate of former problem drinkers is the highest. （ C） Researchers have explained the reason why abstainers face high risk of dying. （ D） Comparing with
48、the abstainers, heavy drinkers are at a lower risk of dying. 18 What kind of people can be considered as a moderate drinker? （ A） People who drink less than three drinks per day. （ B） People who drink red wine. （ C） People who only drink with family members. （ D） Drinkers whose purpose is to improve
49、 health. 19 Why would abstaining from alcohol lead to a shorter life according to the passage? （ A） Because people who abstain from alcohol are in lower status. （ B） Because people who have to abstain from alcohol tend to face more stresses. （ C） Because abstaining from alcohol is a painful experience. （ D） Because abstainers have already incurred health problems. 20 According to the research over a 20-year period, what kind of people has the highest mortality rates? （ A） Those who drunk before that
