1、大学英语四级模拟试卷 398及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write A Letter to Congratulate Your Friend Who Has Recently Won a Scholarship. You should write at least 120 words following the outline given below in Chinese: 1. 得知好友刚获得一等奖学金，对他表示祝贺 2对他所取得的成绩加以评价 3表达
2、美好祝愿，并再次表示祝贺 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 giv
3、en 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 How Exercise Makes You Smarter Exercise does more than build muscles and help prevent heart disease. New science shows that it also bo
4、osts brainpower-and may offer hope in the battle against Alzheimer(痴呆症 ). The stereotype of the “dumb jock“ has never sounded right to Charles Hillman. A jock himself, he plays hockey four times a week, but when he isnt body-checking his opponents on the ice, hes giving his mind a comparable workout
5、 in his neuroscience and kinesiology lab at the University of Illinois. Recently he started wondering if there was a vital and overlooked link between brawn and brains-if long hours at the gym could somehow build up not just muscles, but minds. With colleagues, he started an experiment. He rounded u
6、p 259 Illinois third and fifth graders, measured their body-mass index and put them through classic PE routines: the “sit-and-reach“, a brisk run and timed push-ups and sit-ups. Then he checked their physical abilities against their math and reading scores on a statewide standardized test. Sure enou
7、gh, on the whole, the kids with the fittest bodies were the ones with the fittest brains, even when factors such as socioeconomic status were taken into account. Sports, Hillman concluded, might indeed be boosting the students intellect. Hillmans study, which will be published later this year, isnt
8、definitive enough to stand alone. But it doesnt have to: it is part of a recent and rapidly growing movement in science showing that exercise can make people smarter. Other scientists have found that vigorous exercise can cause nerve cells to form dense, interconnected webs that make the brain run f
9、aster and more efficiently. And there are clues that physical activity can stay away from the beginnings of Alzheimers disease, ADHD and other cognitive disorders. No matter your age, it seems, a strong, active body is crucial for building a strong, active mind. Some scientists have always suspected
10、 as much, although they have not been able to prove it. Now, however, armed with brain-scanning tools and a sophisticated understanding of biochemistry, researchers are realizing that the mental effects of exercise are far more profound and complex processes than they once thought. The processes sta
11、rt in the muscles. When the exercise is available, the muscle sends out chemicals, including a protein called IGF-1 that travels through the bloodstream, across the blood-brain barrier and into the brain itself. And then the brain issues orders fuels almost all the activities that lead to higher tho
12、ught. With regular exercise, the body builds up its levels of BDNF, and the brains nerve cells start to branch out, join together and communicate with each other in new ways. This is the process that underlies learning: every change in the junctions between brain cells signifies a new fact or skill
13、thats been picked up for future use. BDNF makes that process possible. Brains with more of it have a greater capacity for knowledge. On the other hand, says UCLA neuroscientist Fernando G6mez-Pinilla, a brain thats low on BDNF shuts itself off to new information. Most people maintain fairly constant
14、 levels of BDNF in adulthood. But as they age, their individual neurons (神经 )slowly start to die off. Until the mid-90s, scientists thought the loss was permanent-that the brain couldnt make new nerve cells to replace the dead ones. But animal studies over the last decade have overturned that assump
15、tion, showing that “neurogenesis“ (神经发生 )in some parts of the brain can be induced easily with exercise. Last weeks study, published in the Proceedings of the National Academy of Sciences, extended that principle to humans for the first time. After working out for three months, all the subjects appe
16、ared to regain new neurons. This, too, might be BDNF at work, transforming stem cells into full-grown, functional neurons. “It was extremely exciting to see this exercise effect in humans for the first time,“ says Scott Small, a Columbia University Medical Center neurologist who coauthored the study
17、 with Salk Institute neurobiologist Fred Gage. “In terms of trying to understand what it means, the field is just exploding.“ As far as scientists know, the new neurons created by exercise are produced in only one place: the dentate gyrus, an area that controls learning and memory. This region helps
18、 the brain match names to faces-one of the first skills to erode as we age. New neurons cant grow throughout the rest of the brain. But other regions benefit from exercise in many secondary ways. Blood volume, like brain volume, increases with exercise. Active adults have less inflammation in the br
19、ain. They also have fewer “little possibility of strokes that can impair cognition without the person even knowing,“ says Kristine Yaffe, a neuroscientist from University of California. Still other researchers have found that athletes have more cells that support neurons and increase neurotransmitte
20、rs after theyre used to send messages from cell to cell. And even the levels of those neurotransmitters are higher in people who exercise frequently. Unlike neurogenesis, which can take weeks to occur, most of these additional effects appear almost immediately. Get off the treadmill (踩单车 ) after a h
21、alf-hour workout, says Hillman, and “within 48 minutes“ your brain will be in better shape. But alas, these benefits are somewhat transient(短暂的 ). Like weight, mental fitness has to be maintained. New neurons, and the connections between them, will stick around for years, but within a month of inact
22、ivity, “it will shrink down, and then the neurons dont function as well anymore,“ says William Greenough, a psychologist at the University of Illinois. Let your body go, then, and your brain will follow. To keep the effects, youve got to keep working out. “If youre thinking that by exercising at age
23、 20 youre going to have some effect on what youre like at age 70,“ Greenough adds, youd better be willing to commit to 50 years of hitting the gym. Unless, that is, youre a kid. Most studies of exercise and cognition have focused on older people-the folks who are just starting to worry that their mi
24、nds arent what they used to be-but the effects of physical exertion on the brain arent limited to that group at all. In fact, in young children, theyre even more potent. Exercise probably has “a more long-lasting effect on brains that are still developing,“ says Phil Tomporowski, a professor of exer
25、cise science at the University of Georgia. In kids, as in adults, the brain reaps many benefits from exercise. This wont surprise parents of kids with ADHD, many of whom already use physical activity as a substitute or supplement for drugs. 2 What is the new benefit of exercise found by those scient
26、ists? （ A） It can build muscles. （ B） It can prevent heart disease. （ C） It can keep people healthy. （ D） It can improve brainpower. 3 Whats the conclusion that Charles Hillman got from his experiment? （ A） Exercise can keep students healthy. （ B） Exercise can improve students brainpower. （ C） Exerc
27、ise can prevent students from disease. （ D） Exercise can help students build muscles. 4 As some scientists have found, the vigorous exercise can make nerve cells to form interconnected webs that make the brain run _. （ A） steadily and more effectively （ B） faster and more efficiently （ C） more power
28、fully （ D） more effectively 5 With the brain-scanning tools and understanding of biochemistry, researchers found the mental effects of exercise start in _. （ A） the brain （ B） the bloodstream （ C） the muscles （ D） the arms 6 What is the running course of IGF-I in improving peoples brainpower? （ A） m
29、uscle-brain-bloodstream （ B） bloodstream-muscle-brain （ C） muscle-bloodstream-brain （ D） bloodstream-brain-muscle 7 During the process of learning, every change in the connection between brain cells signifies an acquired _. （ A） new fact or information （ B） new image and skill （ C） new fact and skil
30、l （ D） new fact or skill 8 Those animals studies have shown that the “neurogenesis“ in some parts of the brain can be regained by _. （ A） doing exercise （ B） taking medical treatment （ C） having a good rest （ D） learning more knowledge 9 As far as scientists know, the new neurons created by exercise
31、 are only produced in the dentate gyrus controlling _. 10 According to William Greenough, if there is no exercise within a month, the new neurons, and the connections between them will _. 11 According to Phil Tomporowski, compared with those older people, effects of exercise on the brains are probab
32、ly more long-lasting to those _. Section A Directions: 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 the questions will be spoken only once. After each
33、 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） Where was the massage left. （ B） What the person said about Margaret. （ C） When the message was left. （ D） What information the person left. （ A） Shes pro
34、bably been in and out all week. （ B） She is probably not here on Sunday. （ C） She has probably no free time this week. （ D） She has probably tried to call. （ A） Check if the status of the television is ready. （ B） Help the woman buy a new television before Friday. （ C） Fix the womans television. （ D
35、） Order a new television for the woman. （ A） The movie did not get any reviews. （ B） The movie was worth the price. （ C） Its a pity the woman didnt watch the movie. （ D） He agrees with the woman about the movie. （ A） He was preparing for next weeks exam. （ B） He wishes he could go to the movie. （ C）
36、 He didnt like watching movies. （ D） He has seen the movie before. （ A） She is a chemist and has to do lots of experiments. （ B） He must be extremely careful. （ C） He is very careless during the experiment. （ D） She doesnt think the man is right. （ A） The man should buy a meal ticket every month. （
37、B） Paying each meal separately will save lots of money. （ C） Buying the meal ticket wont save the man money. （ D） The price of each meal is different. （ A） She will help him make the model. （ B） She completed her model quickly. （ C） She is very smart and clever. （ D） She thinks he can also finish it
38、 quickly. （ A） Searching for reference material. （ B） Watching a film of the 1930s. （ C） Writing a course book. （ D） Looking for a job in a movie studio. （ A） Its too broad to cope with. （ B） Its a bit outdated. （ C） Its controversial. （ D） Its of little practical value. （ A） At the end of the onlin
39、e catalogue. （ B） At the Reference Desk. （ C） In The New York Times. （ D） In the Readers Guide to Periodical Literature, （ A） He disliked the topic of the lecture. （ B） He didnt want to go to the lecture. （ C） He thought the professor was not famous. （ D） He wasnt present at the lecture. （ A） The Ar
40、ctic land. （ B） Iceberg. （ C） Active volcano. （ D） Ice age. （ A） The active volcanoes in the Antarctic. （ B） The icebergs and volcanoes around the world. （ C） How to prevent the eruption of volcanoes. （ D） Volcano can protect ice sheet from melting. （ A） Professor Smith is her uncle. （ B） He is Prof
41、essor Jamisons assistant. （ C） She used to do the job herself. （ D） She has just applied for the job. Section B Directions: In this section, 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 yo
42、u hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） The first Olympics were held in 767B.C. （ B） The games were held to honor Athena. （ C） The games were held every two years. （ D） All wars were ceased during the games. （ A） 100-meter race. （ B） 200-me
43、ter race. （ C） Wrestling. （ D） Marathon. （ A） Wrestling. （ B） Racing. （ C） Pole jumping. （ D） Boxing. （ A） They were offered free dinners for life. （ B） They were recruited as guards of honor. （ C） They traveled freely inside the state. （ D） They received awards in the temple of Zeus. （ A） Nearly 90
44、 percent of groceries are packed in plastic bags. （ B） Plastic bags are used everywhere in the world. （ C） Almost one trillion plastic bags are used each year. （ D） Plastic bags contain poisonous chemicals. （ A） Plastic bags take hundreds of years to break down. （ B） Plastic bags are sighted in Arct
45、ic Ocean and close to Antarctica. （ C） Plastic bags have been washed up in Antarctica. （ D） Plastic bags are killing many sea turtles. （ A） He has stolen the thrown away pills. （ B） He practiced medicine without a license in Africa. （ C） Thrown away pills can not he given away. （ D） He has not repor
46、ted his doing to the court. （ A） The loss of natural habitat for many species. （ B） Less space for building new homes. （ C） Less carbon dioxide and oxygen. （ D） Reduced supply of paper and wood. （ A） Continued rainfalls. （ B） The increase of carbon dioxide. （ C） The disappearance of grasslands. （ D）
47、 Less land for cows and sheep. （ A） Reusing and recycling paper. （ B） Prohibiting tree cutting. （ C） Planting more trees than they cut down. （ D） Reducing emissions of carbon dioxide. Section C Directions: In this section, you will hear a passage three times. When the passage is read for the first t
48、ime, 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 heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For thes
49、e blanks, you can either use the exact words you have just heard or write down the 36 It should be kept in mind that crying is the natural province of the infant. Babies come into this world and most immediately begin crying, and they will use this communication【 B1】 _of pre-language development to communicate all their【 B2】 _. But, studies also show that boys cries may be ignored for【 B3】_longer, and especially in certain cultures, girls cries are【
