1、大学英语四级改革适用（阅读）模拟试卷 159及答案与解析 Section C 0 How does food affect mood and mind? The answer may lie in the chemistry of the brain and nervous system. Molecules called neurotransmitters (神经传递素 ) are chemical messengers. They carry a nerve impulse across the gap between nerve cells. The release of neurotr
2、ansmitter molecules from one neuron and their attachment to receptor sites on another keep a nerve impulse moving. Nerve impulses carry messages from the environment to the brain, for example, the pain you feel when you stub (踢碰 ) your toe. They also carry messages in the other direction, from the b
3、rain to the muscles. Thats why you back away from the obstacle that initiated the pain signal and exclaim, “Ouch! “ “Many neurotransmitters are built from the foods we eat,“ says neuroscientist Eric Chudler of the University of Washington. Too little or too much of a particular nutrient in the diet
4、can affect their production, Chudler says. For example, tryptophan from foods such as yogurt, milk, bananas, and eggs is required for the production of the neurotransmitter serotonin. Phenylalanine from beets, almonds, eggs, meat, and grains goes into making the neurotransmitter dopamine. Dozens of
5、neurotransmitters are known; hundreds may exist. Their effects depend on their amounts and where they work in the brain. The neurotransmitter serotonin, for example, is thought to produce feelings of calmness, relaxation, and contentment. Drugs that prevent it from being taken again (into the neuron
6、 that released it) are prescribed to treat depression. In at least some healthy, nondepressed people, carbohydrate foods seem to enhance serotonin production and produce similar effects. “It is the balance between different neurotransmitters that helps regulate mood,“ Chudler says. Proper nutrition
7、may also enhance brainpower. Choline is a substance similar to the B vitamins. Its found in egg yolks, whole wheat, peanuts, milk, green peas, liver, beans, seafood, and soybeans. The brain uses it to make the neurotransmitter acetylcholine. To test the effects of choline on memory and learning, res
8、earchers at the Massachusetts Institute of Technology gave memory tests to college students before increasing the amount of choline in their subjects diets. Later, they retested. On the average, memories were better, and the students learned a list of unrelated words more easily. 1 The function of n
9、eurotransmitters can be best compared to that of_. （ A） a transport vehicle （ B） a protective shield （ C） a power plant （ D） a food factory 2 According to the second paragraph, messages sent from the brain to the muscles make you_. （ A） feel the pain （ B） stub your toe （ C） see an obstacle （ D） excl
10、aim “Ouch“ 3 When is depression resulted? （ A） When the level of serotonin is low. （ B） When the level of serotonin is high. （ C） When serotonin is released from neurons. （ D） When people eat carbohydrate foods. 4 Researchers at the Massachusetts Institute of Technology intended to find out_. （ A） h
11、ow choline is produced out of foods （ B） how choline is converted into acetylcholine （ C） if the improvement of brainpower is related to choline （ D） if the improvement of brainpower is related to proper diets 5 What is the message the author intends to convey? （ A） The chemistry of the brain and ne
12、rvous system. （ B） The influence of foods on our mood and mind. （ C） The functions of neurotransmitters. （ D） The importance of a balanced diet. 5 Like a needle climbing up a bathroom scale, the number keeps rising. In 1991, 15% of Americans were obese (肥胖的 ); by 1999, that proportion had grown to 2
13、7%. Youngsters, who should have age and activity on their side, are growing larger as well: 19% of Americans under 17 are obese. Waistbands have been popping in other western countries too, as physical activity has declined and diets have expanded. By and large, people in the rich world seem to have
14、 lost the fight against flab (松弛 ). Meanwhile, poorer nations have enjoyed some success in their battles against malnutrition and famine. But, according to research presented at the annual meeting of the American Association for the Advancement of Science, it is more a case of being out of the fryin
15、g pan and into the fire. The most striking example actually in the poor world comes from the Pacific islands, home of the worlds most obese communities. In 1966, 14% of the men on this island were obese while 100% of men under the age of 30 in 1996 were obese. This increase in weight has been uneven
16、 as well as fast. As a result, undernourished and over-nourished people frequently live cheek by jowl (面颊 ). The mix can even occur within a single household. A study of families in Indonesia found that nearly 10% contained both the hungry and the fat. This is a mysterious phenomenon, but might have
17、 something to do with people of different ages being given different amounts of food to eat. The prospect of heading off these problems is bleak. In many affected countries there are cultural factors to contend with, such as an emphasis on eating large meals together, or on food as a form of hospita
18、lity. Moreover, there is a good measure of disbelief on the part of policymakers that such a problem could exist in their countries. Add to that reluctance on the part of governments to spend resources on promoting diet and exercise while starvation is still a real threat, and the result is a recipe
19、 for inaction. Unless something is done soon, it might not be possible to turn the clock back. 6 The first sentence of the passage most probably implies that_. （ A） many Americans are obsessed with the rising temperature in their bathroom （ B） more people are overweighed in the United States （ C） pe
20、ople are doing more physical exercises with the help of scales （ D） youngsters become taller and healthier thanks to more activities 7 As physical exercise declines and diet expands, _. （ A） other western countries has been defeated by fat （ B） obesity has become an epidemic (流行病 ) of the rich world
21、 （ C） waistbands begin to be popular in other western countries （ D） western countries can no longer fight against obesity 8 Which is NOT the point of the example of the Pacific Islands? （ A） The poor community has shaken off poverty and people are well-fed now. （ B） Obesity is becoming a problem in
22、 the developing world too. （ C） Excessive weight increase will cause no less harm than the food shortage. （ D） The problem of overweight emerges very fast. 9 Of tackling obesity in the poor world, we can learn from the passage that _. （ A） the matter is so complex as to go beyond our capacity （ B） n
23、o matter what we do, the prospect will always be bleak （ C） it is starvation, the real threat, that needs to be solved （ D） we should take immediate actions before it becomes incurable 10 What is the main idea of this passage? （ A） Obesity is now a global problem that needs tackling. （ B） The weight
24、s increase fast throughout the whole world. （ C） Obesity and starvation are two main problems in the poor world. （ D） Obesity has shifted from the rich world to the poor world. 10 On a more mundane (世俗的 ) level, third-generation mobile telephones, despite all the delays and the billions squandered o
25、n 3G licenses by telecom firms, are still expected to offer consumer highspeed, always-on mobile internet access, complete with video, in the next few years. Rapidly proliferating “wi-fi“ (无线局域网 ) networks already offer wireless access on a local basis. Tiny tracking chips called radio-frequency ide
26、ntification devices are being used as passports. Soon they will be small, powerful and cheap enough to be implanted into everything. Sensors of every kind, including video cameras, should also become much smaller and cheaper. Forrester Research, a technology consultancy, predicts that 14 billion suc
27、h devices will be connected to the internet by 2005. How rapidly such new technology is introduced will depend on a number of factorsthe state of the economy, the supply of investment capital and the appetite of consumers for new products or services! Fortunes will be made and lost many times over.
28、But whatever happens, the power of computing and communications looks set to continue to grow, and its price to fall, at a steady rate for the next few decades. That will make it possible, at least in rich countries, to record most human interactions, wherever and whenever they take place, and to st
29、ore and analyze this ocean of data at low cost. For the sake of argument, this survey will assume that we are heading towards a networked society of ubiquitous (到处存在的 ), mobile communication capable of constant monitoring. Whether this arrives in 20, 30 or 40 years does not really matter. The point
30、is that the destination seems not merely possible, but probable, so it is not too soon to ask: What do we want this technology to do? The internet has already thrown up a host of legal and political problems, but these are only a small foretaste of the dilemmas about privacy, security, intellectual
31、property and the nature of government itself that will have to be faced over the coming decades. The debate has already begun. This survey will outline some of main issues, and speculate on the way they are likely to go. 11 At present, a radio-frequency identification device enables people to _. （ A
32、） get small, powerful and cheap passports （ B） get wireless access to the “wi-fi“ networks （ C） get smaller and cheaper sensors of every kind （ D） get wireless internet access complete with video 12 According to Forrester Research, _. （ A） 3G mobile phones will be more widely used （ B） the tiny trac
33、king chips will be more powerful （ C） the wireless networks will provide a wider coverage （ D） sensors of every kind will become smaller and cheaper 13 By saying “its price to fall“ (line 4, Para. 2), the author means that_. （ A） the cost of computing and communications will fall （ B） the cost of ne
34、w technology will fall （ C） the cost of new products will fall （ D） the cost of recoding human interactions will fall 14 Which of the following best describes the problems derived from the internet? （ A） The internet has helped solve many legal and political problems. （ B） The internet will produce
35、more than legal and political problems. （ C） Problems involved with the internet are too complicated to solve. （ D） Problems involved with the internet will be solved within decades. 15 The passage is most probably _ of a research paper. （ A） the introductory part （ B） the conclusion part （ C） the s
36、upporting data （ D） the new findings 15 Of all the components of a good nights sleep, dreams seem to be least within our control. In dreams, a window opens into a world where logic is suspended and dead people speak. A century ago, Freud stated that dreams were the disguised shadows of our unconscio
37、us desires and fears; by the late 1970s, neurologists (神经学家 ) had switched to thinking of them as just “mental noise“. Now researchers suspect that dreams are part of the minds emotional thermostat, regulating moods while the brain stops thinking logically. And one leading authority says that these
38、intensely powerful mental events can be not only harnessed but actually brought under conscious control, to help us sleep and feel better. “Its your dream,“ says Rosalind Cartwright, chair of psychology at Chicagos Medical Center. “If you dont like it, change it.“ The link between dreams and emotion
39、s shows up among the patients in Cartwrights clinic. Most people seem to have more bad dreams early in the night, progressing toward happier ones before awakening, suggesting that they are working through negative feelings generated during the day. (In studying divorced couples, Cartwright has found
40、 that those who dont follow this dream progression have a much harder time getting over the hurt.) Because our conscious mind is occupied with daily life we dont always think about the emotional significance of the days events until, it appears, we begin to dream. And this process need not be left t
41、o the unconscious. Cartwright believes one can exercise conscious control over repeated bad dreams. As soon as you awaken, identify what is upsetting about the dream. Imagine how you would like it to end instead; the next time it occurs, try to wake up just enough to control its course. With much pr
42、actice people can learn to, literally, do it in their sleep. At the end of the day, theres probably little reason to pay attention to our dreams at all unless they keep us from sleeping or we wake up in a panic. Terrorism, economic uncertainties and general feelings of insecurity have increased peop
43、les anxiety. Those suffering from persistent nightmares should seek help from a therapist. For the rest of us, sleep or rather dream on it and youll feel better in the morning. 16 By saying that “dreams are part of the minds emotional thermostat,“ (Line 5, Para. 1) the researchers mean that _. （ A）
44、we can think logically in the dreams too （ B） dreams can be brought under conscious control （ C） dreams represent our unconscious desires and fears （ D） dreams can help us keep our mood comparatively stable 17 What did Cartwright find in her clinic? （ A） Most bad dreams were followed by happier ones
45、. （ B） Divorced couples usually have more bad dreams. （ C） Ones dreaming process is related to his emotion. （ D） People having negative feelings dream more often. 18 Cartwright believed with much practice, we can learn to _. （ A） control what dreams to dream （ B） sleep well without any dreams （ C） w
46、ake up in time to stop the bad dreams （ D） identify what is upsetting about the dreams 19 The author points out that a person who has constant bad dreams should_. （ A） learn to control his dreams （ B） consult a doctor （ C） sleep and dream on it （ D） get rid of anxiety first 20 The author most probab
47、ly thinks that controlling dreams is _. （ A） a good practice （ B） a new discovery （ C） helpful for everyone （ D） not essential for everyone 大学英语四级改革适用（阅读）模拟试卷 159答案与解析 Section C 【知识模块】 仔细阅读 1 【正确答案 】 A 【试题解析】 从第 1段第 3句末的 messenger和第 4句中的 carryacross 可以知道 neurotransmitters就像传递信息的信使，有 “运输、输送 ”信息的功能，因此
48、，本题应选 A。 【知识模块】 仔细阅读 2 【正确答案】 D 【试题解析】 第 2段第 3句开头的 Thats why 表明当信息从大脑传到肌肉的时候，会使你躲开障碍物并发出 “哎哟 ”的叫声， D就是这两个动作的其中之一，故为答案。 A最具干扰性，因为 pain一词在第 3句也有提及，但根据本段第一句可知 A应属于 “信息从肌肉传到大脑 ”的过程，和题干中的 from the brain to the muscles正好相反，因此， A并不正确。 【知识模块】 仔细阅读 3 【正确答案】 A 【试题解析】 第 4段第 5句末的 similar effects指的是 “同样可以使人不再情绪低
49、落 ”，由此可见，本句指出了 serotonin的含量高，情绪就不会低落，反过来说，serotonin的含量低就会导致情绪低落，这就是 A的内容。 C项具有干扰性，但原文并没有依据表明神经元细胞释放 serotonin时人的情绪就会低落，故不选 。 【知识模块】 仔细阅读 4 【正确答案】 C 【试题解析】 最后一段第 5句开头的 To test the effects of choline on memory and learning明确表明了麻省理工学院的研究目的是为了找到 choline对学生记忆和学习的影响，记忆和学习都与 “脑力 ”有关，由此可见， C是对这个研究目的的正确描述，为本题答案。 【知识模块】 仔细阅读 5 【正确答案】 B 【试题解析】 本文首句提出的问题是全文要解答的问题，也就是说，全文围绕这个问题展开 讨论，由此可见，本文是为了说明食物对情绪和思维的影响，因此，本题应选 B。 A可以说是第 1段至第 4段的主要内容， C是第 1段的内容，均没有全面概括全文内容。 D中的 balanced diet在文中不断提及，但本文的重点不是为了说明均衡饮食的重要性，而是饮食和情绪、思维的
