1、大学英语四级模拟试卷 712及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write a composition entitled Changes in Average Housing Space in Hejiang City. You should write at least 120 words following the outline given below in Chinese: 1. 河江市人均住房情况的变化 2. 造成这些变化的原因所在 3. 人均住房情况
2、的变化可能引发的问题 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 attached to the passage. For questions 1-7, mark： Y (for YES) if the statement agrees with the information given
3、 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. 1 Inside a small chamber at a Kent State University laboratory, hamsters sleep, eat, play and rest while fluid flows in and out of tubes t
4、hreaded through their tiny brains. It took biology professor J. Da vid Glass two years to set up the finicky dialysis system, which measures a key neurotransmitter in the biological clocks of these nocturnal rodents. His payoff came in 1996, when he became the first re searcher to measure serotonin
5、levels rising and falling in the biological clock area of the brain during an animals daily cycle. Serotonin is the “feel good“ chemical manipulated by widely prescribed drugs such as Prozac. Meanwhile, in a larger chamber down the hall, Glass is monitoring tropical monkeys. He has found that exerci
6、se and arousal from sleep have major impacts on the biological rhythms of the monkeys, permanently shifting their clocks in the absence of normal daylight and darkness cues. Glasss research and that of others could have implications for the millions of people who take com monanti-depressants and oth
7、er drugs that affect serotonin in the brain. It has long been known that the substance is a key player in the biological clock, and that the region has an unusually high concentration of receptors for the neurotransmitter. Glasss work is part of the fast-growing field of circadian(or daily)rhythm re
8、search focused on a region at the base of the brain, the size of a corn kernel, that scientists discovered 25 years ago is the bodys timing mechanism. Like other animals and even plants, humans have built-in clocks that regulate internal functions on a 24-hour basis. For most mammals, the clocks tri
9、gger sleep and waking, as well as metabolism, hor mone levels, body temperature and many other changes. This is a particularly exciting time for circadian-rhythm researchers. In recent times, scientists at universities in Illinois, Texas and Japan have found genes involved with the clock, including
10、one that appears to be a basic building block of the mechanism and is common across all species, from fruit flies to humans. Meanwhile, researchers like Glass, whose work has attracted US $1.2 million(9.6 mil lion RMB)in grants from the National Institute of Health, are trying to understand how the
11、clock works. Sitting on top of the optic nerve, the clock is heavily influenced by light. But other factors, too, are involved in resetting the mechanism, most notably physical activity and substances like serotonin. Glass and his students found that, when lights in the hamster chamber were switched
12、 off, the serotonin levels in the rodentsclock region shot up: hamsters are nocturnal, meaning they rest during the day and are awake at night. But when hamsters in the midst of their sleep cycle were put onto an activity wheel, a significant rise in serotonin levels was measured in those hamsters t
13、hat woke up enough to ex ercise. It has long been known that serotonin is key to body clock function, according to Thomas Wehr, a scientist at the National Institute of Mental Health in Bethesda, Maryland. Researchers at the Mary land Institute took cells from the clock region of the brain, sprinkle
14、d serotonin on them and, by monito ring electrical impulses, watched the cells “reset“ themselves. “There are certain drugs used with humans that have also been squirted on these cells in dishes and have been shown to reset the clock in the dish, so it seems quite possible there are similar effects
15、in hu mans who take these drugs. “Wehr says. Indeed, some people taking anti-depressants do report sleep disorders such as insomnia or daytime drowsiness that could be related to changes in their biological clocks. Human studies have yet to focus on the issue. Studies have found that serotonin affec
16、ts the clock in different ways, depending on the point in the cells daily cycle that it is administered. Glass recently completed an experiment using marmosets, small monkeys native to Central and South America. Researchers moved a sleeping marmoset to anoth er cage, then monitored it as it scurried
17、 around its new environment. After this burst of activity, the marmoset shifted its cycles forward or backward a few hours, and they remained shifted, apparently in definitely. Cycles were pushed back when the disruption occurred early in the sleep period; they shifted forward when the disruption oc
18、curred late in the cycle. According to Glass, the experiment demonstrates what scientists have known anecdotally for a long time: that exercise, when performed at certain times, shifts our clocks. Exercise has long been recommended to speed recovery from jet lag, for example. That may be because exe
19、rcise boosts serotonin. Glass found he could mimic the effect of the arousal experiment by injecting a serotonin like drug and believes the findings suggest something similar could be expected in people. “Were getting closer and closer to making the link that humans can adjust their circadian clock
20、through natural means such as exercise, “Glass says. 2 Prozac is the “feel good“ chemical manipulated by widely prescribed drugs. （ A） Y （ B） N （ C） NG 3 For most mammals, metabolism, hormone levels, body temperature and many other changes are not triggered by clocks. （ A） Y （ B） N （ C） NG 4 Light i
21、s one of the important factors that influence the clock. （ A） Y （ B） N （ C） NG 5 According to the passage, monkeys, like human beings are worried about the change of clocks that triggered the body nerve. （ A） Y （ B） N （ C） NG 6 Insomnia or daytime drowsiness that related biological clocks were not f
22、ocused on by human studies. （ A） Y （ B） N （ C） NG 7 When the disruption occured in the cycle, cycles were pushed back. （ A） Y （ B） N （ C） NG 8 The clock, however, can be affected by serotonin in different ways, depending on the point in the cells daily cycle. （ A） Y （ B） N （ C） NG 9 But when hamster
23、s in the midst of their sleep cycle were put onto an activity wheel, _. 10 Glass has found that _ have major impacts on the biological rhythms of the monkeys. 11 Exercise has long been recommended to _. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversatio
24、ns. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and 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 be
25、st answer. （ A） The man is very satisfied with the woman in the future. （ B） The man will find the woman another job. （ C） The man will hire the woman. （ D） The man probably wont hire the woman. （ A） Children dont get enough education safety. （ B） Children are keen on dangerous games. （ C） The playg
26、rounds are in poor condition. （ D） The playgrounds are overcrowded. （ A） Because he cant find his office key. （ B） Because he has misplaced some exams. （ C） Because hes unable to talk. （ D） Because he doesnt like his classroom. （ A） Teach Dons class while he is absent. （ B） Give Professor Webster th
27、e key to Dons office. （ C） Make an appointment with the doctor. （ D） Return some exams to the students. （ A） To put the homework on Dons desk. （ B） To leave the key for Don. （ C） To give Dons students the next assignment. （ D） To call Don at the end of the afternoon. Section B Directions: In this se
28、ction, you will hear 3 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） England won the World Cup. （ B） Br
29、itain joined the European community. （ C） The Channel Tunnel was opened. （ D） Britain was invaded by the Romans. （ A） America and Spain. （ B） Russia, Japan and Cuba. （ C） Italy, Germany, Scandinavia and France. （ D） Portugal, India and Tunisia. （ A） The Atlantic Tunnel. （ B） The Pacific Tunnel. （ C）
30、 The Caribbean Tunnel. （ D） The Channel Tunnel. （ A） Her husband had got a higher position. （ B） Her husband had lost his job. （ C） She wanted to have a cleaner house. （ D） She wanted to move to New York. （ A） His telephone went out of order. （ B） The buyers had to leave soon. （ C） He began to work
31、at 8 a. m. （ D） He had made an appointment with her for 8 a. m. （ A） They considered her lazy. （ B） They saw something they had never seen. （ C） They considered her foolish. （ D） They saw something familiar to them. （ A） By lifting her to the platform. （ B） By helping her rise to her feet. （ C） By p
32、ulling her along the ground. （ D） By dragging her away from the edge. Section C Directions: 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 requi
33、red to fill in the blanks numbered from 36 to 43 with the exact words you have just 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 24 Perched among the highlands
34、of western Cameroon, bordered by green mountains and cliff laces, Lake Nyos is a scene of breathtaking beauty. But the picture cannot be 【 B1】 _. A detailed study reveals that the lake could release a 【 B2】 _ cloud of carbon dioxide, capable of wiping out entire communities around its shores. The wa
35、rning, from a team of scientists, comes nearly 20 years after the lake 【 B3】_ an estimated 80m cubic metres of CO2 into the atmosphere. Heavier than air, the cloud of gas rolled down, 【 B4】 _ hillsides and villages. Silent and invisible, it 【 B5】 _ the air of oxygen, killing hundreds of cattle and c
36、laiming the lives of more than 1,700 people up to 26 km away. “It was one of the most mysterious 【 B6】_ scientists have ever investigated,“ said George Kling, an ecologist at the University of Michigan. Researchers called in after the 1986 【 B7】 _ discovered that the lake, which sits atop a volcano,
37、 contained record levels of carbon dioxide. Gas bubbling up from the Earths magma was under such 【 B8】 _ at the bottom of the 200-metre-deep lake that it dissolved until it reached max. 【 B9】 _. To prevent a recurrence, in 2001 engineers installed a pipe to suck CO2 from the bottom of the lake and r
38、elease it harmlessly into the air. 【 B10】 _. Dr Klings team recommends the urgent installation of a further four pipes in each lake at a rate of one a year. 【 B11】 _. 24 【 B1】 25 【 B2】 26 【 B3】 27 【 B4】 28 【 B5】 29 【 B6】 30 【 B7】 31 【 B8】 32 【 B9】 33 【 B10】 34 【 B11】 Section A Directions: In this se
39、ction, there is a passage with ten blanks. You are required to select one word for each blank from 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 correspon
40、ding 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. 34 This is for people who are interested in adopting a low-fat lifestyle or for those who are already living a low-fat lifestyle. My husband and I【 S1】 _consume 2040 grams of
41、 fat each day. I【 S2】_grams of fat rather than calculate the percentage of fat/calories because I find it much【 S3】 _and less complicated. Our daily fat percentage of calories【 S4】_from 10% to 20%. Today we have lost a【 S5】 _amount of weight and we are very healthy and full of energy. Living a low-f
42、at lifestyle is not【 S6】 _, it just takes a little organization and a commitment to change the way you eat as a lifestyle change, not as adieu. The problem with a diet is that when you think about【 S7】 _on a diet, you think of it as having a beginning and an end. The【 S8】 _is the problem. I have bee
43、n on【 S9】_diets in my lifetime and lost more weight than I care to think about, only to gain it all back in less time than it took to lose it! Making a【 S10】 _to living a low-fat lifestyle for the rest of your life is the key. A)end I)difficult B)presently J)going C)significant K)count D)numerous L)
44、symbolic E)easier M)committee F)hops N)means G)presumably O)runs H)commitment 35 【 S1】 36 【 S2】 37 【 S3】 38 【 S4】 39 【 S5】 40 【 S6】 41 【 S7】 42 【 S8】 43 【 S9】 44 【 S10】 Section B Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. Fo
45、r each of them there are four choices marked A, B, C and D. You should decide on the best choice. 44 I was 13 when Benji came into our lives. With his deep brown eyes, floppy ears and cheerful disposition, he was my constant companion throughout my teenage years. We would play together in the garden
46、, and take long walks over the hills behind the house and being a dog, he seemed to have a sympathy for my problems that went deeper than words could express. He was my best friend. Benji left us about 15 years ago for that great kennel in the sky. But recently Ive been thinking about him a lot. Was
47、 he really conscious? Could any animal have consciousness like we do? Does it matter whether animals are conscious or not? For many, it is a matter of life and death. On the one hand, animal research has helped prevent some of the most pressing human diseases, including hepatitis B, hepatitis C, “ma
48、d cow“ disease, malaria, cystic fibrosis and emphysema. On the other hand, this research is performed largely on chimps, our closest nonhuman relatives, with whom we share 98.4% of our genetic material, and great apes, with whom we are similarly biologically close. Some people feel this connection is strong enough to warrant special treatment. An international group called the Great Ape Project is lobbying the United Nations to adopt a declaration on the rights of great apes modeled on the UN declaration On the Rights of Man. The group believes that apes are “c
