1、大学英语四级改革适用（阅读）模拟试卷 280 及答案解析(总分：60.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：6，分数：60.00)1.Part III Reading Comprehension（分数：10.00）_2.Section C（分数：10.00）_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)
2、are chemical messengers. They carry a nerve impulse across the gap between nerve cells. The release of neurotransmitter 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 exampl
3、e, the pain you feel when you stub (踢碰) your toe. They also carry messages in the other direction, from the brain 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 neuroscienti
4、st Eric Chudler of the University of Washington. Too little or too much of a particular nutrient in the diet 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. Phenyla
5、lanine from beets, almonds, eggs, meat, and grains goes into making the neurotransmitter dopamine. Dozens of 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 fee
6、lings of calmness, relaxation, and contentment. Drugs that prevent it from being taken again (into the neuron 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
7、is the balance between different neurotransmitters that helps regulate mood,“ Chudler says. Proper nutrition 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 u
8、ses it to make the neurotransmitter acetylcholine. To test the effects of choline on memory and learning, researchers 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 avera
9、ge, memories were better, and the students learned a list of unrelated words more easily.（分数：10.00）(1).The function of neurotransmitters can be best compared to that of_.（分数：2.00）A.a transport vehicleB.a protective shieldC.a power plantD.a food factory(2).According to the second paragraph, messages
10、sent from the brain to the muscles make you_.（分数：2.00）A.feel the painB.stub your toeC.see an obstacleD.exclaim “Ouch“(3).When is depression resulted?（分数：2.00）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 carbohy
11、drate foods.(4).Researchers at the Massachusetts Institute of Technology intended to find out_.（分数：2.00）A.how choline is produced out of foodsB.how choline is converted into acetylcholineC.if the improvement of brainpower is related to cholineD.if the improvement of brainpower is related to proper d
12、iets(5).What is the message the author intends to convey?（分数：2.00）A.The chemistry of the brain and nervous system.B.The influence of foods on our mood and mind.C.The functions of neurotransmitters.D.The importance of a balanced diet.Like a needle climbing up a bathroom scale, the number keeps rising
13、. In 1991, 15% of Americans were obese (肥胖的); by 1999, that proportion had grown to 27%. 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
14、declined and diets have expanded. By and large, people in the rich world seem to have 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 Ass
15、ociation for the Advancement of Science, it is more a case of being out of the frying 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
16、 men under the age of 30 in 1996 were obese. This increase in weight has been uneven 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% con
17、tained both the hungry and the fat. This is a mysterious phenomenon, but might have 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,
18、such as an emphasis on eating large meals together, or on food as a form of hospitality. 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 di
19、et and exercise while starvation is still a real threat, and the result is a recipe for inaction. Unless something is done soon, it might not be possible to turn the clock back.（分数：10.00）(1).The first sentence of the passage most probably implies that_.（分数：2.00）A.many Americans are obsessed with the
20、 rising temperature in their bathroomB.more people are overweighed in the United StatesC.people are doing more physical exercises with the help of scalesD.youngsters become taller and healthier thanks to more activities(2).As physical exercise declines and diet expands, _.（分数：2.00）A.other western co
21、untries has been defeated by fatB.obesity has become an epidemic (流行病) of the rich worldC.waistbands begin to be popular in other western countriesD.western countries can no longer fight against obesity(3).Which is NOT the point of the example of the Pacific Islands?（分数：2.00）A.The poor community has
22、 shaken off poverty and people are well-fed now.B.Obesity is becoming a problem in 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.(4).Of tackling obesity in the poor world, we can learn from the passag
23、e that _.（分数：2.00）A.the matter is so complex as to go beyond our capacityB.no matter what we do, the prospect will always be bleakC.it is starvation, the real threat, that needs to be solvedD.we should take immediate actions before it becomes incurable(5).What is the main idea of this passage?（分数：2.
24、00）A.Obesity is now a global problem that needs tackling.B.The weights 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.On a more mundane (世俗的) level, third-generation mobile telephon
25、es, despite all the delays and the billions squandered on 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 loca
26、l basis. Tiny tracking chips called radio-frequency identification 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,
27、 a technology consultancy, predicts that 14 billion such 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 ser
28、vices! Fortunes will be made and lost many times over. 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 interac
29、tions, wherever and whenever they take place, and to store 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
30、 20, 30 or 40 years does not really matter. The point 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
31、of the dilemmasabout privacy, security, intellectual property and the nature of government itselfthat 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.（分数：10.00）(1).At present, a
32、radio-frequency identification device enables people to _.（分数：2.00）A.get small, powerful and cheap passportsB.get wireless access to the “wi-fi“ networksC.get smaller and cheaper sensors of every kindD.get wireless internet access complete with video(2).According to Forrester Research, _.（分数：2.00）A.
33、3G mobile phones will be more widely usedB.the tiny tracking chips will be more powerfulC.the wireless networks will provide a wider coverageD.sensors of every kind will become smaller and cheaper(3).By saying “its price to fall“ (line 4, Para. 2), the author means that_.（分数：2.00）A.the cost of compu
34、ting and communications will fallB.the cost of new technology will fallC.the cost of new products will fallD.the cost of recoding human interactions will fall(4).Which of the following best describes the problems derived from the internet?（分数：2.00）A.The internet has helped solve many legal and polit
35、ical problems.B.The internet will produce 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.(5).The passage is most probably _ of a research paper.（分数：2.00）A.the introductory p
36、artB.the conclusion partC.the supporting dataD.the new findingsOf 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 s
37、hadows of our unconscious 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 auth
38、ority says that these 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 betw
39、een dreams and emotions 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
40、, Cartwright has found 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 eventsuntil, it appears, we begin to dream. And this proce
41、ss need not be left to 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
42、 course. With much practice 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 insecurit
43、y have increased peoples anxiety. Those suffering from persistent nightmares should seek help from a therapist. For the rest of us, sleepor rather dreamon it and youll feel better in the morning.（分数：10.00）(1).By saying that “dreams are part of the minds emotional thermostat,“ (Line 5, Para. 1) the r
44、esearchers mean that _.（分数：2.00）A.we can think logically in the dreams tooB.dreams can be brought under conscious controlC.dreams represent our unconscious desires and fearsD.dreams can help us keep our mood comparatively stable(2).What did Cartwright find in her clinic?（分数：2.00）A.Most bad dreams we
45、re followed by happier ones.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.(3).Cartwright believed with much practice, we can learn to _.（分数：2.00）A.control what dreams to dreamB.sleep well without a
46、ny dreamsC.wake up in time to stop the bad dreamsD.identify what is upsetting about the dreams(4).The author points out that a person who has constant bad dreams should_.（分数：2.00）A.learn to control his dreamsB.consult a doctorC.sleep and dream on itD.get rid of anxiety first(5).The author most proba
47、bly thinks that controlling dreams is _.（分数：2.00）A.a good practiceB.a new discoveryC.helpful for everyoneD.not essential for everyone大学英语四级改革适用（阅读）模拟试卷 280 答案解析(总分：60.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：6，分数：60.00)1.Part III Reading Comprehension（分数：10.00）_解析：2.Section C（分数：10.00）_解析：How does f
48、ood 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 neurotransmitter 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
