1、大学英语六级模拟试卷 312及答案与解析 一、 Part I Writing (30 minutes) 1 Directions: For this part, you are allowed 30 minutes to write a composition on the topic Income Sources of American and Chinese students. You should write at least 150 words following the outline given below in Chinese:1. 根据图标说明中美大学生的来源 2. 分析可能产
2、生这种不同现象的原因 3. 提出个人的建议二、 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 1-4, mark： Y (for YES) if the statement agrees with the informa
3、tion 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. 1 Fishes The term fish is applied to a variety of cold-blooded aquatic vertebrates of several evolutionary lines. Fish share cer
4、tain features with other vertebrates. These features are gill slits (鳃裂 ) at some point in the life cycle, a notochord (脊索 ), or skeletal supporting rod, a dorsal hollow nerve cord, and a tail. The study of fishes, the science of ichthyology (鱼类学 ), is of broad importance. There are many reasons why
5、 fishes are of interest to humans; the most important is their relationship with and dependence on the environment. A more obvious reason for interest in fishes is their role as a moderate but important part of the worlds food supply. This resource, once thought unlimited, is now realized to be fini
6、te and in delicate balance with the biological, chemical, and physical factors of the aquatic environment. Overfishing, pollution, and alteration of the environment are the chief enemies of proper fisheries management, both in fresh waters and in the ocean. Another practical reason for studying fish
7、es is their use in disease control. As predators on mosquito larvae, they help curb malaria and other mosquito borne diseases. Fishes are valuable laboratory animals in many aspects of medical and biological research. For example, the readiness of many fishes to acclimate to captivity has allowed bi
8、ologists to study behaviour, physiology, and even ecology under relatively natural conditions. Fishes have been especially important in the study of animal behaviour where research on fishes has provided a broad base for the understanding of the more flexible behaviour of the higher vertebrates. The
9、re are aesthetic and recreational reasons for an interest in fishes. Millions of people keep live fishes in home aquariums for the simple pleasure of observing the beauty and behaviour of animals otherwise unfamiliar to them. To many, aquarium fishes provide a personal challenge, allowing them to te
10、st their ability to keep a small section of the natural environment in their homes. Sportfishing is another way of enjoying the natural environment, also indulged in by millions of people every year. Interest in aquarium fishes and sportfishing support multimillion dollar industries throughout the w
11、orld. Fishes have been in existence for more than 450,000,000 years, during which time they have evolved repeatedly to fit into almost every conceivable type of aquatic habitat. In a sense, land vertebrates are simply highly modified fishes, for when fishes colonized the land habitat they became tet
12、rapod (四足的 ) land vertebrates. The popular conception of a fish as a slippery, streamlined aquatic animal that possesses fins and breathes by gills applies to many fishes, but far more fishes deviate from that conception than conform to it. For example, the body is elongate in many forms and greatly
13、 shortened in others; the body is flattened in some (principally in bottom-dwelling fishes) and laterally compressed in many others; the fins may be elaborately extended, forming intricate shapes, or they may be reduced or even lost; and the positions of the mouth, eyes, nostrils, and gill openings
14、vary widely. Air breathers have appeared in several evolutionary lines. Many fishes are cryptically coloured and shaped, closely matching their respective environments; others are among the most brilliantly coloured of all organisms, with a wide range of hues, often of striking intensity, on a singl
15、e individual. The brilliance of pigments may be enhanced by the surface structure of the fish, so that it almost seems to glow. A number of unrelated fishes have actual light-producing organs. Many fishes are able to alter their coloration, some for the purpose of camouflage, others for the enhancem
16、ent of behavioral signals. Fishes range in adult length from less than 10 millimetres to more than 20 metres and in weight from about 1.5 grams to many thousands of kilograms. Some live in shallow thermal springs at temperatures slightly above 42 (100F), others in cold Arctic seas a few degrees belo
17、w 0 (32T) or in cold deep waters more than 10,000 metres beneath the ocean surface. The structural and, especially, the physiological adaptations for life at such extremes are relatively poorly known and provide the scientifically curious with great incentive for study. Almost all natural bodies of
18、water bear fish life, the exceptions being very hot thermal ponds and extremely salt-alkaline lakes such as the Dead Sea and Great Salt Lake in Utah. The present distribution of fishes is a result of the geological history and development of the Earth as well as the ability of fishes to undergo evol
19、utionary change and to adapt to the available habitats. Fishes may be seen to be distributed according to habitat and according to geographical area. Major habitat differences are marine and fresh waters. For the most part the fishes in them, even in adjacent areas, are different, but some, such as
20、the salmon, migrate from one to the other. The freshwater habitat may be seen to be of many kinds. Fishes found in mountain torrents, Arctic lakes, tropical lakes, temperate streams, and tropical rivers will all differ from each other both in obvious gross structure and in physiological attributes.
21、Even in closely adjacent habitats where, for example, a tropical mountain torrent enters a lowland stream, the fish fauna will differ. Marine habitats can be divided into deep ocean floors, midwater oceanic, surface oceanic, rocky coast, sandy coast, muddy shores, bays, estuaries, and others. Also,
22、for example, rocky coastal shores in tropical and temperate regions will have a different fish fauna, even when such habitats occur along the same coastline. Although much is known about the present geographical distribution of fishes, far less is known about how that distribution came about. Many p
23、arts of the fish fauna of the fresh waters of North America and Eurasia are related and undoubtedly have a common origin. The faunas of Africa and South America are related, extremely old, and probably an expression of the drifting apart of the two continents. The fauna of southern Asia is related t
24、o that of central Asia and some of it appears to have entered Africa. The extremely large shore fish faunas of the Indian and tropical Pacific oceans comprise a related complex, but the tropical shore fauna of the Atlantic, although containing Indo-Pacific components, is relatively limited and proba
25、bly younger. The Arctic and Antarctic marine faunas are quite different from each other. The shore fauna of the North Pacific is quite distinct, and that of the North Atlantic more limited and probably younger. Pelagic oceanic fishes, especially those in deep waters, are similar the world over, show
26、ing little geographical isolation in terms of family groups. The deep oceanic habitat is very much the same throughout the world, but species differences do exist, showing geographical areas determined by oceanic currents. 2 All aspects of the life of a fish are closely correlated with adaptation to
27、 the total environment, physical, chemical, and biological. （ A） Y （ B） N （ C） NG 3 Millions of people keep live fishes in home aquariums for biological research. （ A） Y （ B） N （ C） NG 4 Many fishes are able to alter their coloration only to camouflage themselves. （ A） Y （ B） N （ C） NG 5 Fishes help
28、 curb malaria and other mosquito-borne diseases by eating mosquito larvae. （ A） Y （ B） N （ C） NG 6 Nearly all natural water bodies bear fish life excepting _. 7 _ is quite different from the Arctic marine fauna. 8 The features of a fish include a notochord, gill slits, _. 9 Sportfishmen are enjoyers
29、 of _. 10 Fishes structural and physiological adaptations for life at extremes are still waiting for _. 11 Overfishing, pollution, and alteration of the environment are _ to the finite fishes resouce. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations
30、. 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 best
31、 answer. （ A） Looking for a new job. （ B） Taking a suburban excursion. （ C） Looking for an apartment. （ D） Asking the man to do her a favor. （ A） 8.5 hours （ B） 7.5 hours. （ C） 8 hours. （ D） 9 hours. （ A） Change the walls color. （ B） Rearrange the furniture. （ C） Buy some fine furniture. （ D） Hang s
32、ome pictures. （ A） He may see Alan in Italy. （ B） He was looking for Alan in the library. （ C） Hes not sure which way to go. （ D） He may have made a mistake. （ A） Wait for the lecture to begin. （ B） Go immediately to their seats. （ C） Get something to drink first. （ D） Sit down and enjoy the lecture
33、. （ A） He doesnt think hell do that. （ B） He finds it easy to do that. （ C） He has no time to do that. （ D） He can help her. （ A） She doesnt need an umbrella. （ B） She left her umbrella in the car. （ C） She can hold her umbrella over the mans head. （ D） Shes the only one who doesnt have an umbrella.
34、 （ A） Its too windy. （ B） The people there are terrible. （ C） The air is polluted. （ D） The beaches are dirty. （ A） The birds wont learn to keep away from people. （ B） She might change her major. （ C） There are more endangered species in zoos than in the wild. （ D） She wasnt quite ready to come back
35、 to campus. （ A） Making puppets. （ B） Training baby birds. （ C） Cleaning cages. （ D） Counting wildlife. （ A） To study animal behavior in the wild. （ B） To increase the publics understanding of endangered species. （ C） To prepare endangered species for life in the wild. （ D） To breed animals to sell
36、to zoos. （ A） Yesterday morning. （ B） Yesterday noon. （ C） Yesterday afternoon. （ D） Yesterday evening. （ A） He doesnt have good qualifications. （ B） His resume hasnt outlined his past in a proper way. （ C） He is not nervous when taking an interview. （ D） He always thinks that the interviewer is lik
37、e an enemy. （ A） He should outline his past better. （ B） He should send his resume directly to the manager. （ C） He should create a new area in his resume called “value offered“. （ D） He neednt write different resume to different employers. （ A） A shipping company. （ B） A consulting company. （ C） An
38、 accounting company. （ D） A headhunting company. 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 you hear a question, you must choose the best answer fr
39、om the four choices marked A, B, C and D. （ A） Early miners. （ B） Spanish explorers. （ C） African naturalists. （ D） Early industrialists. （ A） To work in mining operations. （ B） To carry scientific supplies. （ C） To cross the North American continent. （ D） To help cultivate the frontier. （ A） Burros
40、 are relatives of the horse. （ B） Burros can adapt easily. （ C） Burros are common farm annals. （ D） There are many burros in the United States. （ A） They help to cure anxiety. （ B） They help patients to gain insight into the cause of anxiety. （ C） They help to control anxiety. （ D） They help patient
41、s to work efficiently. （ A） They reduce a persons appetite. （ B） They make a person less persistent in face of trouble. （ C） They make a persons nervous system weak. （ D） They make a person more vulnerable to disease. （ A） Prejudiced. （ B） Enthusiastic. （ C） Indifferent. （ D） Objective. （ A） The str
42、ength of its shipbuilding industry. （ B） The physical features of the river itself. （ C） The abundance of fruit, vegetables, and livestock. （ D） The similarity of climate to that in Europe. （ A） There are no rapids or waterfalls. （ B） There is a constant, strong wind. （ C） Navigation is rather diffi
43、cult. （ D） Frequent storms cause problems for riverboats. （ A） Big waves pose a threat to commercial navigation. （ B） The river current never flows faster ten miles per hour. （ C） The river reverses its flow several times a day. （ D） High tides can create sudden and unexpected rapids. （ A） To allow
44、several sails to be rigged. （ B） To add to the beauty of the basic design. （ C） To catch winds coming from over the hills. （ D） To allow the sails to be raised more quickly Section C Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you sh
45、ould 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 these blanks, y
46、ou can either use the exact words you have just heard or write down the 36 More and more, the operations of our businesses, governments, and【 B1】 _ institutions are controlled by information that exists only inside computer memories. Anyone clever enough to【 B2】 _ this information for his own purpos
47、es can reap (收割 ) substantial rewards. Even worse, a number of people who have done this and been caught at it have【 B3】 _ to get away without punishment. Its easy for computer crimes to go【 B4】 _ if no one checks up on what the computer is doing. But even if the crime is detected, the criminal may
48、walk away not only unpunished but with a glowing【 B5】 _ from his former employers. Of course, we have no【 B6】 _ on crimes that go undetected. But its【 B7】_ to note how many of the crimes we do know about were detected by accident, not by systematic inspections or other【 B8】 _ procedures. The compute
49、r criminals who have been caught may be the victims of uncommonly bad luck. For example, a certain keypunch operator complained of having to stay overtime to punch extra cards. Investigation revealed that the extra cards she was being asked to punch were for dishonest transactions.【 B9】 _ Unlike other lawbreakers, who must leave the country, commit suicide, or go to jail,【 B10】 _ All too often, their demands have been met. Why?【 B11】 _ .
