1、大学英语四级模拟试卷 965（无答案）一、Part I Writing (30 minutes)1 For this part you are allowed 30 minutes to write a composition entitled How People Spend Their Holidays. You may put down what conclusion youve drawn from the figures shown in the following table, and then give your reasons for these changes.You cou
2、ld begin your writing like this: The way people spent their holidays has changed a great deal over the past few years .二、Part II Reading Comprehension (Skimming and Scanning) (15 minutes)Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attach
3、ed to the passage. For questions 1-7, mark：Y (for YES) if the statement agrees with the information given in the passage;N (for NO) if the statement contradicts the information given in the passage;NG (for NOT GIVEN) if the information is not given in the passage.2 Weight-Loss Nirvana?A Substance Th
4、at Makes Fat Mice Thin Just Might Work for Humans TooIn the US, where one in three adults is seriously overweight, the news carried by the journal Science last week - that Friedman and his colleagues at the Howard Hughes Medical Institute and New York Citys Rockefeller University had discovered a ma
5、gical dose that melts fat in a matter of weeks - resonated with unusual force. Momentarily, at least, it encouraged the spirits of millions of lifelong dieters and boosted the stock of Amgen, the biotechnical firm based in California that holds the license on the underlying technology. It is too ear
6、ly to predict, however, whether this rare elixir (called leptin, after the Greek leptos, meaning slender) will be a stunning pharmaceutical (制药上的) success or just another “miracle“ cure that never pans out. Even if all goes well, it could be five to ten years before leptin is approved in the US for
7、human use. Researchers must first demonstrate that leptin benefits people as well as animals and that it causes no serious side effects.The search for leptin began in the 1960s, when Douglas Coleman, a researcher at the Jackson Laboratory in Bar Harbor, Maine, began studying a strain of fat laborato
8、ry mice. In a series of creative experiments, Coleman surgically joined the blood vessels of an .obese (肥胖的) mouse to those of a normal-size mouse, creating a sort of artificial Siamese twin. What happened then was astonishing: the fat animal immediately began to lose weight. This suggested that the
9、 blood of non-obese mice carried an effective biochemical messenger, one that played an important role in regulating appetite and metabolism (新陈代谢). But the mysterious agent was present in such minuscule quantities that no one was able to isolate it.Friedman picked up the challenge, applying new too
10、ls developed by the field of molecular genetics. The secret factor, he reasoned, must be produced by a gene that was defective in the obese mice. So he began to hunt for such a gene, the ob, or obese, gene. Sure enough, late last year, after eight years of effort, Friedman and his colleagues pinpoin
11、ted the ob gene in both average-weight and obese mice. They then inserted the normal gene into bacterial (细菌的) cells, providing at long last detectable quantities of the protein they called leptin.By injecting leptin into obese mice, three separate teams of researchers, including Friedmans, have con
12、firmed that this protein is indeed the blood factor that makes fat mice thin. But they are still trying to puzzle out just how it works. Friedman, for one, believes leptin is almost certainly a hormone that travels through the bloodstream to act on the brain. In fact, it appears leptin may act in a
13、feedback loop (反控循环) like the temperature sensor in a thermostat (恒温器)-or in this case a “fatstat“ - to tell the body whether to turn metabolism and appetite up or down. Thus when leptin is low, hunger pangs increase, body temperature drops, and metabolism slows; when leptin is high, everything reve
14、rses. In such fashion, the brain strives to keep body weight stable and fluctuations small.Because leptin is produced in fat tissue (组织), the fatter an animal is, the more leptin its cells should make. Normal mice then respond to weight gain by turning out more leptin. As a result, their appetites s
15、low down and their energy consumption speeds up. But the obese mice cannot produce leptin, so their brains never receive this vital message. “These animals,“ says Friedman, “get fat because they think theyre starving, and then when we give them the protein, they get thin because they think theyre fa
16、t!“What, if anything, does this have to do with people? Perhaps a good deal. For humans have an ob gene that is virtually the same as the mouse gene, and it is possible that at least some folks have trouble keeping off kilos because of mutation (突变) in this gene. Most experts, however, agree that de
17、fects in the ob gene are not likely to be a major reason for obesity in people. But that does not mean leptin might not be therapeutically (治疗学的) useful for many other overweight people. In last weeks Science, for example, a team of researchers from the pharmaceutical company Hoffmann-LaRoche descri
18、bed how they fattened lean mice by giving them unrestricted access to high-fat food. Then they administered leptin. The mice responded by cutting their food intake and shedding the extra grams, suggesting leptin may have value in reversing more typical cases of weight gain.What about side effects? I
19、njections of leptin do not, as one might fear, turn lean mice into starving wretches. After losing weight, researchers from Amgen reported, normal mice stabilize both their food intake and their metabolism. Obese mice likewise reach an ideal leanness, and then stop losing weight. The pattern of weig
20、ht loss is also encouraging. For unlike extreme calorie restriction, which can weaken muscle, leptin appears to melt fat while leaving lean tissue untouched. On the basis of such data, Amgen (which paid Rockefeller University $ 20 million for patent rights to make products based on the ob gene) has
21、announced that it hopes to begin making human trials as early as next year. Many experts find these plans too optimistic. Just because researchers have not noted worrisome side effects yet, critics say, does not mean that none will emerge. Leptin, they point out, is a serious drug, not the easy-to-s
22、wallow “thin pill“ dieters have dreamed of for so long. To do its work, leptin would probably have to be either injected daily or implanted under the skin for life. In the laboratory experiments reported last week, the obese mice started regaining weight as soon as the injections stopped. Even with
23、a boost from something like leptin, cautions Dr. Ahmed Kissebah, an obesity expert at the Medical College of Wisconsin, the formerly fat cannot afford to become less alert. “People will still have to lose weight the hard way,“ he predicts. “Itll be like diabetes: you still have to exercise and watch
24、 your food intake.“Regardless of what eventually happens in the marketplace, the discovery of leptin is occasion for celebration. It has provided scientists with a new way for exploring a still poorly understood metabolic pathway, one that probably consists of many other equally powerful compounds,
25、each of which could lead to new drugs. To the millions of seriously overweight Americans, help with a frustrating condition - years of guilty eating and self-recrimination - may finally be on the way.2 Leptin is effective in reducing weight but its many years away before humans can use it.（A）Y（B） N（
26、C） NG3 Leptin, after being approved by health authorities, will be available to people in need through doctors prescriptions.（A）Y（B） N（C） NG4 Both obese mice and normal mice have the ob gene.（A）Y（B） N（C） NG5 Both obese mice and normal mice can produce leptin in their bodies.（A）Y（B） N（C） NG6 Dr. Frie
27、dman never found the gene that was believed to control weight. Instead, he found leptin.（A）Y（B） N（C） NG7 If excess leptin is present, the brain signals the body to increase food intake and to become more active.（A）Y（B） N（C） NG8 The ob gene causes the fat cells to produce the hormone leptin. The fatt
28、er, the more hormones are produced.（A）Y（B） N（C） NG9 Leptin plays an important role in adjusting _ and metabolism.10 After being _ leptin, the obese mice start consuming less food and burning more fat, which is confirmed by Friedman together with three separate teams of researchers.11 In response to
29、_, normal mice will turn out more leptin that will speed up their energy consumption.Section ADirections: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and
30、 the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer.（A）Its very traditional.（B） Its terrific.（C） Its too modern.（D）Its enjoyable.（A）He stayed up too late last ni
31、ght.（B） He went to bed too early last night.（C） He went to the zoo with his son yesterday.（D）He worked overtime yesterday.（A）The woman met Jim by chance last Friday.（B） The man contacted Jim on business three months ago.（C） The man received a phone call from Jim last Friday.（D）The woman injured Jim
32、in a traffic accident last Friday.（A）Buy a dictionary for herself.（B） Take a dictionary out of the library.（C） Use whatever dictionaries in the library.（D）Borrow a dictionary from Professor Smith.（A）He is fond of drinking coffee.（B） Professor Blacks lectures were interesting.（C） He skipped Professor
33、 Blacks classes.（D）Professor Blacks lectures were boring.（A）He prefers shorter working hours.（B） He expects a vacation.（C） He prefers to have a higher position.（D）He wants to earn more money.（A）Meeting each other at the railway station.（B） Complaining about the poor service.（C） Discussing their plan
34、 for New Years Day.（D）Saying goodbye to each other at the railway station.（A）Submitted his opinion.（B） Read the suggestions in haste.（C） Formed a proposal.（D）Calculated his income tax.（A）He can manage his time more flexibly.（B） He can renew contact with his old friends.（C） He can concentrate on his
35、own projects.（D）He can learn to do administrative work.（A）Reading its ads in the newspapers.（B） Calling its personnel department.（C） Contacting its manager.（D）Searching its website.（A）To cut down its production expenses.（B） To solve the problem of staff shortage.（C） To improve its administrative eff
36、iciency.（D）To utilize its retired employees resources.（A）Its about the change of peoples taste.（B） Its about the organic food and organic farming.（C） Its about the development of agriculture.（D）Its about the healthy problem.（A）Its the biggest apple among all the apples produced.（B） Its the most beau
37、tiful apple among all the apples produced.（C） Its the sweetest apple among all the apples produced.（D）Its the cheapest among all the apples produced.（A）Its prospect has not been positive so far but more and more people begin to change their mind.（B） It will be accepted by all people very soon.（C） Mo
38、re and more farmers use organic farming to produce food although it reduces the profit of them.（D）It grows fast and more and more farmers use organic farming to produce food.（A）In a radio studio.（B） In a farming land.（C） In a TV show.（D）In a lab.Section BDirections: In this section, you will hear 3
39、short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D.（A）The Irish.（B） The Blacks.（C） The Chinese.（D）The Indians.（A）T
40、he victory over ones fellow runners.（B） The victory over former winners.（C） The victory of will-power over fatigue.（D）The victory of ones physical strength.（A）The runner who runs to keep fit.（B） The runner who breaks the record.（C） The runner who does not break the rules.（D）The runner who covers the
41、 whole distance.（A）He won the first prize.（B） He fell behind the other runners.（C） He died because of fatigue.（D）He gave up because he was tired.（A）For the sake of high grades.（B） For passing given examinations.（C） For the good of gaining knowledge.（D）For the completion of required assignments.（A）To
42、 complete them with the aid of their tutors.（B） To accomplish them mainly through their own efforts.（C） To read all the reference books assigned by the professors.（D）To go over all the periodicals, articles and books in the library.（A）Look for him in his office.（B） Consult him outside of class.（C） M
43、ake an appointment with him.（D）Talk to him during classroom hours.（A）Because they get low grades.（B） Because they exhaust the reference sources in the library.（C） Because they can spend only limited time with the professors.（D）Because their teachers do not grade every assignment of them.Section CDir
44、ections: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just
45、 heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the 34 French Defense Minister Michele Alliot-Marie says her government is【B1】_to help train Iraqs police and military
46、 but rules out sending French【B2 】 _there. The French official made her【B3】_Friday in Washington, where she is【B4】_to smooth relations that soured over Frances opposition to the U. S.-led war in Iraq.Ms. Alliot Marie told a【B5】_at the Center for【B6】_and International Studies in Washington that Franc
47、e would be【B7】_to help train Iraqs future military and police forces,【B8】_to what France and Germany are doing in Afghanistan.Ms. Alliot-Marie, a close political ally of President Chirac,【B9】_, which soured over French opposition to the U. S. -led war in Iraq.“【B10】_,“ said Michele Alliot-Marie. “We
48、 simply want to promote our vision of things as we respect that of others.【B11】_35 【B1 】36 【B2 】37 【B3 】38 【B4 】39 【B5 】40 【B6 】41 【B7 】42 【B8 】43 【B9 】44 【B10 】45 【B11 】Section ADirections: In this section, there is a passage with ten blanks. You are required to select one word for each blank from
49、a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item with a single line through the center. You may not use any of the words in the bank more than once.45 In the 1960s, many people in North America turned their attention to environmental problems, and new steel-and-gla
