[外语类试卷]大学英语六级模拟试卷309及答案与解析.doc

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1、大学英语六级模拟试卷 309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 Proposal of Banning Disposable Chopsticks. You should write at least 150 words following the outline given below in Chinese: 1. 发出倡议的根据、原因和目的 2. 要求做到的具体事项 3

2、. 表示倡议者的决心和希望 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 information gi

3、ven 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 Rivers By original usage, a river is flowing water in a channel with defined banks. Modern usage includes rivers that are multichanne

4、led, intermittent, or ephemeral in flow and channels that are practically bankless. The concept of channeled surface flow, however, remains central to the definition. Rivers are nourished by precipitation, by direct overland runoff, through springs and seepages, or from meltwater at the edges of sno

5、wfields and glaciers. The contribution of direct precipitation on the water surface is usually minute, except where much of a catchment area is occupied by lakes. River water losses result from seepage into shallow or deep aquifers (沙石含水层 ) and particularly from evaporation. The difference between t

6、he water input and loss sustains surface discharge or streamflow. The amount of water in river system at any time is but a tiny fraction of the Earths total water; 97 percent of all water is contained in the oceans and about three-quarters of fresh water is stored as land ice; nearly all the remaind

7、er occurs as groundwater. Lakes hold less than 0.5 percent of all fresh water, soil moisture accounts for about 0.05 percent, and water in river channels for roughly half as much, 0.025 percent, which represents only about one four-thousandth of the Earths total fresh water. Water is constantly cycl

8、ed through the systems of land ice, soil, lakes, groundwater (in part), and river channels, however. The discharge of rivers to the oceans delivers to these systems the equivalent of the water vapour that is blown overland and then consequently precipitated as rain or snow, e., some 7 percent of mea

9、n annual precipitation on the globe and 30 percent of precipitation on land areas. The historical record includes marked shifts in the appreciation of rivers, numerous conflicts in use demand, and an intensification of use that has rapidly accelerated during the 20th century. External freight trade

10、became concentrated in estuarine ports (河口港 ) rather than in inland ports when ocean-going vessels increased in size. Demand on open-channel water increases as population and per capita water use increase and as underground water supplies fall short. Irrigation use constitutes a comparatively large

11、percentage of the total supply. Present-day demands on rivers as power sources range from the floating of timber, through the use of water for cooling, to hydroelectric generation. Logging in forests relies primarily on flotation during the season of melt-water high flow. Large power plants and othe

12、r industrial facilities are often located along rivers, which supply the enormous quantities of water needed for cooling purposes. Manufacturers of petrochemicals, steel, and woolen cloth also make large demands. Hydroelectric power generation was introduced more than 100 years ago, but the majority

13、 of the existing installations have been built since 1950. The ever-increasing exploitation of rivers has given rise to a variety of problems. Extensive commercial navigation of rivers has resulted in much artificial improvement of natural channels, including increasing the depth of the channels to

14、permit passage of larger vessels. In some cases, this lowering of the river bottom has caused the water table of the surrounding area to drop, which has adversely affected agriculture. Also, canalization, with its extensive system of locks and navigation dams, often seriously disrupts riverine ecosy

15、stems. An even more far-reaching problem is that of water pollution. Pesticides and herbicides are now employed in large quantities throughout much of the world. The widespread use of such biocides and the universal nature of water makes it inevitable that the toxic chemicals would appear as stream

16、pollutants. Biocides can contaminate water, especially of slow flowing rivers, and are responsible for a number of fish kills each year. In agricultural areas the extensive use of phosphates and nitrates as fertilizers may result in other problems. Entering rivers via rainwater runoff and groundwate

17、r seepage, these chemicals can cause eutrophication (水体加富过程 ). This process involves a sharp increase in the concentration of phosphorus, nitrogen, and other plant nutrients that promotes the rapid growth of algae in sluggish rivers and a consequent depletion of oxygen in the water. Under normal con

18、ditions, algae contribute to the oxygen balance in rivers and also serve as food for fish, but in excessive amounts they crowd out populations of other organisms, overgrow, and finally die due to the exhaustion of available nutrients and autointoxication (自身毒物 ). Various species of bacteria then beg

19、in to decay and putrefy the dead algal bodies, the oxidation of which sharply reduces the amount of oxygen in the river water. The water may develop a bad taste and is unfit for human consumption unless filtered and specially treated. Urban centres located along rivers contribute significantly to th

20、e pollution problem as well. In spite of the availability of advanced waste-purification technology, a surprisingly large percentage of the sewage from cities and towns is released into waterways untreated. In effect, rivers are used as open sewers for municipal wastes, which results not only in the

21、 direct degradation of water quality but also in eutrophication. Still another major source of pollutants is industry. Untreated industrial chemical wastes can alter the normal biological activity of rivers, and many of the chemicals react with water to raise the acidity of rivers to a point where t

22、he water becomes corrosive enough to destroy living organisms. An example of this is the formation of sulfuric acid from the sulfur laden residue of coalmining operations. Although upper limits for concentrations of unquestionably toxic chemicals have been established for drinking water, no general

23、rules exist for the treatment of industrial wastes because of the wide variety of organic and inorganic compounds involved. Moreover, even in cases where a government-imposed ban checks the further discharge of certain dangerous substances into waterways, the chemicals may persist in the environment

24、 for years. Such is the case with PCBs (多氯化联苯 ). Since PCBs cannot be broken down by conventional waste-treatment methods and are degraded by natural processes very slowly, scientists fear that these compounds will continue to pose a serious hazard for decades to come. PCBs have been found in high c

25、oncentrations in the fatty tissues of fish, which can be passed up the food chain to humans. An accumulation of PCBs in the human body is known to induce cancer and other severe disorders. As noted above, many industrial facilities, including nuclear power plants, steel mills, chemical-processing fa

26、cilities, and oil refineries, use large quantities of water for cooling and return it at elevated temperatures. Such heated water can alter the existing ecology, sometimes sufficiently to drive out or kill desirable species of fish. It also may cause rapid depletion of the oxygen supply by promoting

27、 algal blooms. 2 The ever-increasing use of rivers has caused different environmental problems. （ A） Y （ B） N （ C） NG 3 Rivers are more effective than coast erosion in delivering rock debris to the sea. （ A） Y （ B） N （ C） NG 4 River water losses happen mainly because of seepage into shallow or deep

28、rock layers. （ A） Y （ B） N （ C） NG 5 Rivers are nourished by direct precipitation, which usually contributes extremely small to the water surface. （ A） Y （ B） N （ C） NG 6 The important part of the definition of a river is _. 7 In historical record, water use demand caused _. 8 What water is constant

29、ly cycled through are _. 9 The algae blooms in sluggish rivers _ oxygen in the water. 10 Urban centers located along rivers result in the fact that _. 11 _ have brought about environmental problems attendant on river use. Section A Directions: In this section, you will hear 8 short conversations and

30、 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 question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and dec

31、ide which is the best answer. （ A） The man should break the candle into two. （ B） The man shouldnt work too hard for the happiness of future. （ C） The man should retire early. （ D） Todays happiness is less important than tomorrows. （ A） She meant he just waited till help came. （ B） She was afraid so

32、mething would go wrong with her ear. （ C） She promised to help him herself. （ D） She meant she could make a phone call if anything went wrong. （ A） Bill will see Kate tomorrow evening. （ B） Bill might be at home late tomorrow evening. （ C） Bill and Kate have decided to go on a holiday. （ D） Bill ask

33、ed the woman to come another time. （ A） She never does things early. （ B） She has already finished it. （ C） She isnt going to finish it. （ D） She will finish it in a few minutes. （ A） He doesnt write well enough. （ B） He doesnt turn in the application. （ C） He hasnt got a professional experience. （

34、D） He didnt perform well in the interview. （ A） The woman is an excellent cook. （ B） The woman is a housewife. （ C） Cathy helped a lot in cooking the dish. （ D） The woman has never cooked before. （ A） The man thinks traveling by air is quite safe. （ B） The woman never travels by plane. （ C） Both spe

35、akers feel nervous when flying. （ D） The speakers feel sad about the serious loss of life. （ A） She had to wait for an appointment. （ B） She had other things to do first. （ C） Her foot had seemed all right. （ D） Her injury had kept him at home. （ A） George and his wife travel abroad for the holiday

36、this year. （ B） George asked a friend for advice about a trip abroad. （ C） George gets some advice from a friend about his possible trip abroad. （ D） George and his wife would like to travel abroad this holiday but they are still hesitating to do so. （ A） George always hesitates at everything. （ B）

37、Georges wife is much too concerned about things at home. （ C） George cant really decide anything at home. （ D） George and his wife hardly go anywhere for holiday year after year because they cant decided where to go. （ A） Whether they can afford the cost of the trip. （ B） Whether someone will take c

38、are of their house, garden and pets while they are away. （ C） Whether they should go by air or by sea. （ D） Whether the trip will keep them away from home for too long. （ A） How different kinds of pepper are produced. （ B） Why white pepper is superior to dishes. （ C） How the pepper plant is grown. （

39、 D） How various peppers are used in cooking. （ A） He read about it in a cookbook. （ B） He grows his own herbs and spices. （ C） He heard about it from a friend. （ D） He studied it in cooking school. （ A） Its preserved in liquid. （ B） The skin is removed. （ C） Its dried in the sun. （ D） Its freeze-dri

40、ed. （ A） He answered all her questions correctly. （ B） He received a good grade in cooking class. （ C） She likes what he has just cooked. （ D） Shes impressed with his knowledge. Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some ques

41、tions. 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） In 1938. （ B） In 1946. （ C） In 1955. （ D） During the World War II. （ A） It reflects commercial interests. （ B） It is a fashi

42、onable professional event. （ C） It is an essential affair or international cinema. （ D） It is more concerned with the art of film than with financial. （ A） It is awarded to the best film of the festival. （ B） It was introduced in 1959. （ C） It was introduced by a commercial organization. （ D） Only A

43、merican directors have received this award. （ A） For the completion of required assignments. （ B） For passing given examinations. （ C） For the good o gaining knowledge. （ D） For the sake of high grades. （ A） To accomplish them mainly through their own efforts. （ B） To complete them with the aid of t

44、heir tutors. （ C） To read all the reference books assigned by the professors. （ D） To get over all the periodicals, articles and books in the library. （ A） Consult him outside of class. （ B） Look for him in the office. （ C） Talk to him during classroom hours. （ D） Make an appointment with him. （ A）

45、Government funded. （ B） Private. （ C） Political. （ D） None of the above. （ A） Wars or natural disasters make them lose their families. （ B） They want to help their families earn enough,mooney to survive. （ C） They are poor. （ D） All the above. （ A） The Philippines. （ B） Mexico. （ C） Brazil. （ D） Gua

46、temala. （ A） Most of the children in developing countries do not receive education or health care. （ B） The chief goal of Child Hope U. S. A is to halt the spread of AIDS and the use of illegal drugs among children. （ C） Child Hope U. S. A cooperates with international childrens groups, government a

47、gencies and other national and local groups. （ D） No children work in Pakistan after the new laws to control child labor was approved. 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

48、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, you can either use the exact words you

49、have just heard or write down the 36 The question of whether war is inevitable is one which has concerned many of the worlds great writers. Before【 B1】 _ this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities directed against one another is【 B2】 _ from competition, defined as opposition among social entities【 B3】 _ striving for something which is in inadequate supply. Competitors may not be aware of one another, wh