[外语类试卷]大学英语六级模拟试卷696及答案与解析.doc

1、大学英语六级模拟试卷 696及答案与解析 一、 Part I Writing (30 minutes) 1 1有些人喜欢跟团旅游 2有些人喜欢自助旅游 3你的看法 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-

2、4, 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. 1 Climate Change Scientists predict increasing droughts, floods and

3、 extreme weather and say there is growing evidence that human activities are to blame. What Is Climate Change? The planets climate is constantly changing. The global average temperature is currently in the region of 15 . Geological and other evidence suggests that, in the past, this average may have

4、 been as high as 27 and as low as 7 . But scientists are concerned that the natural fluctuation (波动 ) has been overtaken by a rapid human-induced warming that has serious implications for the stability of the climate on which much life on the planet depends. What Is the “Greenhouse Effect“? The gree

5、nhouse effect refers to the role played by gases which effectively trap energy from the Sun in the Earths atmosphere. Without them, the planet would be too cold to sustain life as we know it. The most important of these gases in the natural greenhouse effect is water vapor, but concentrations of tha

6、t are changing little and it plays almost no role in modern human-induced greenhouse warming. Other greenhouse gases include carbon dioxide, methane (甲烷 ) and nitrous (含氮的 ) oxide, which arc released by modern industry, agriculture and the burning of fossil fuels. Their concentration in the atmosphe

7、re is increasing-the concentration of carbon dioxide has risen by more than 30% since 1800. The majority of climate scientists accept the theory that an increase in these gases will cause a rise in the Earths temperature. What Is the Evidence of Warming? Temperature records go back to the late 19th

8、century and show that the global average temperature increased by about 0.6 in the 20th century. Sea levels have risen 10 20 cm-thought to be caused mainly by the expansion of warming oceans. Most glaciers in temperate regions of the world and along the Antarctic Peninsula are in retreat, and record

9、s show Arctic sea-ice has thinned by 40% in recent decades in summer and autumn. There are anomalies (异常 ) however-parts of the Antarctic appear to be getting colder, and there are discrepancies between trends in surface temperatures and those in the troposphere(对流层 ) (the lower portion of the atmos

10、phere). How Much Will Temperatures Rise? If nothing is done to reduce emissions, current climate models predict a global temperature increase of 1.4 5.8 by 2100. Even if we cut greenhouse gas emissions dramatically now, scientists say the effects would continue because parts of the climate system, p

11、articularly large bodies of water and ice, can take hundreds of years to respond to changes in temperature. It also takes greenhouse gases in the atmosphere decades to break down. It is possible that we have already irrevocably(不可撤回地 ) committed the Greenland ice sheet to melting, which would cause

12、an estimated 7m rise in sea level. There are also indications that the west Antarctic ice sheet may have begun to melt, though scientists caution further research is necessary. How Will the Weather Change? Globally, we can expect more extreme weather events, with heat waves becoming hotter and more

13、frequent. Scientists predict more rainfall overall, but say the risk of drought in inland areas during hot summers will increase. More flooding is expected from storms and rising sea levels. There are, however, likely to be very strong regional variations in these patterns, and these are difficult t

14、o predict. What Will the Effects Be? The potential impact is huge, with predicted freshwater shortages, sweeping changes in food production conditions, and increases in deaths from floods, storms, heat waves and droughts. Poorer countries, which are least equipped to deal with rapid change, will suf

15、fer most. Plant and animal extinctions are predicted as habitats change faster than species can adapt, and the World Health Organization has warned that the health of millions could be threatened by increases in malaria, water-borne disease and malnutrition. What Dont We Know? We dont know exactly w

16、hat proportion of the observed warming is caused by human activities or what the knock-on effects of the warming will be. The precise relationship between concentrations of carbon dioxide (and other greenhouse gases) and temperature rise is not known, which is one reason why there is such uncertaint

17、y in projections Of temperature increase. Global warming will cause some changes which will speed up further warming, such as the release of large quantities of the greenhouse gas methane as permafrost(永久冻结带 ) melts. Other factors may mitigate(减轻 ) warming. It is possible that plants may take more c

18、arbon dioxide from the atmosphere as their growth speeds up in warmer conditions, though this remains in doubt. Scientists are not sure how the complex balance between these positive and negative feedback effects will play out. What about the Skeptics? Global warming “skeptics“ fall into three broad

19、 camps: - those who maintain temperatures are not rising; - those who accept the climate is changing but suspect it is largely down to natural variation; - those who accept the theory of human-induced warming but say it is not worth tackling as other global problems are more pressing. Nevertheless,

20、there is a growing scientific consensus (舆论 ) that, even on top of the natural variability of the climate, something out of the ordinary is happening and humans are to blame. A scientific report commissioned by the U.S. government has concluded there is “clear evidence“ of climate change caused by h

21、uman activities. The report, from the federal Climate Change Science Program, said trends seen over the last 50 years “cannot be explained by natural processes alone“. It found that temperatures have increased in the lower atmosphere as well as at the Earths surface. However, scientists involved in

22、the report say better data is badly needed. Observations down the years have suggested that the troposphere, the lower atmosphere, is not warming up, despite evidence that temperatures at the Earths surface are rising. This goes against generally accepted tenets (原则 ) of atmospheric physics, and has

23、 been used by “climate skeptics“ as proof that there is no real warming. The new report, Temperature Trends in the Lower Atmosphere, re-analyses the atmospheric data and concludes that tropospheric temperatures are rising. This means, it says, that the impact of human activities upon the global clim

24、ate is clear. “The observed patterns of change over the past 50 years cannot be explained by natural processes alone, nor by the effect of short-lived atmospheric constituents (such as aerosols and tropospheric ozone ) alone,“ it says. Holes in the Data But there are some big uncertainties which sti

25、ll need resolving. Globally, the report concludes, tropospheric temperatures have risen by 0.10 and 0.20 per decade since 1979, when satellite data became generally available. The wide gap between the two figures means, says the report, that “.it is not clear whether the troposphere has warmed more

26、or less than the surface.“ Peter Thorne, of the U.K. Meteorological Office, who contributed to the report, ascribes this uncertainty to poor data “Basically, weve not been observing the atmosphere with climate in mind,“ he told the BBC News website. “Were looking for very small signals in data that

27、are very noisy. From one day to the next, the temperature can change by 10 , but were looking for a signal in the order of 0.1 per decade.“ The report shows up a particular discrepancy concerning the tropics, where it concludes that temperatures are rising by between 0.02 and 0.19 per decade, a big

28、margin of error. Additionally, the majority of the available datasets show more warming at the surface than in the troposphere, whereas most models predict the opposite. For Fred Singer, of the Science and Environmental Policy Project, a prominent climate skeptic, this suggests that the reports supp

29、ort for the concept of human-induced climate change is spin rather than substance. “The basic data in the report is quite OK,“ he said, “but the interpretation thats been given is different from what the data says.“ No Inconsistency Measuring tropospheric temperatures is far from a simple business.

30、Satellites sense the “average“ temperature of the air between themselves and the Earth, largely blind to what is happening at different altitudes. To compound matters, instruments on board satellites degrade over time, orbits subtly drift, and calibration (校准 ) between different satellites may be po

31、or. Weather balloons (or radiosondes) take real-time measurements as they ascend, but scientists can never assess instruments afterwards; they are “fire-and-forget“ equipment. Correcting for all these potential sources of error is a sensitive and time-consuming process. The report makes clear recomm

32、endations for the kind of infrastructure needed to produce higher-quality data and resolve remaining uncertainties. Key recommendations include: - establishing reference sites for radiosonde measurements which would increase consistency between datasets; - making sure the operating periods of satell

33、ites overlap so instruments can be cross-calibrated; -observing factors such as wind, clouds, and humidity in the troposphere to make sure they are consistent with temperature data. Such observations could produce an unambiguous picture of tropospheric warming, removing discrepancies over the scient

34、ific picture and providing better data which can be used to improve computer models. 2 In the past, the global average temperature may have been 27 . （ A） Y （ B） N （ C） NG 3 Water vapor plays almost no role in modern greenhouse warming. （ A） Y （ B） N （ C） NG 4 There are discrepancies between trends

35、in surface temperatures and those in the troposphere in the Antarctic. （ A） Y （ B） N （ C） NG 5 It may take large bodies of water and ice decades to respond to changes in temperature. （ A） Y （ B） N （ C） NG 6 It is difficult to predict the strong regional variations in the patterns of _. 7 According t

36、o the WHO, increases in malaria, water-borne disease and malnutrition could threaten _. 8 The release of large quantities of the greenhouse gas methane as permafrost melts will speed up _. 9 A U.S. scientific report concluded that some trends of climate change were caused by _. 10 Most models predic

37、t more warming in the troposphere than at the surface, whereas most datasets _. 11 To resolve remaining uncertainties, its necessary to observe factors such as wind, clouds, and humidity in the troposphere to make sure they are consistent with _. Section A Directions: In this section, you will hear

38、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 question there will be a pause. During the pause, you must read the four choices mark

39、ed A, B, C and D, and decide which is the best answer. （ A） She isnt going to change her major. （ B） She plans to major in tax law. （ C） She studies in the same school as her brother. （ D） She isnt going to work in her brothers firm. （ A） She will do her best if the job is worth doing. （ B） She pref

40、ers a life of continued exploration. （ C） She will stick to the job if the pay is good. （ D） She doesnt think much of job-hopping. （ A） Stop thinking about the matter. （ B） Talk the drug user out of the habit. （ C） Be more friendly to his schoolmate. （ D） Keep his distance from drug addicts. （ A） Th

41、e son. （ B） The father. （ C） The mother. （ D） Aunt Louise. （ A） Stay away for a couple of weeks. （ B） Check the locks every two weeks. （ C） Look after the Johnsons house. （ D） Move to another place. （ A） He didnt want to warm up for the game. （ B） He didnt want to be held up in traffic. （ C） He want

42、ed to make sure they got tickets. （ D） He wanted to catch as many game birds as possible. （ A） It will reduce government revenues. （ B） It will stimulate business activities. （ C） It will mainly benefit the wealthy. （ D） It will cut the stockholders dividends. （ A） The man should phone the hotel for

43、 directions. （ B） The man can ask the department store for help. （ C） She doesnt have the hotels phone number. （ D） The hotel is just around the corner. （ A） President. （ B） Senator. （ C） Secretary. （ D） Treasurer. （ A） In the afternoon. （ B） In the morning. （ C） During lunch. （ D） During dinner. （

44、A） Make posters. （ B） Write a speech. （ C） Answer questions. （ D） Study for chemistry. （ A） Colleagues. （ B） Boss-Employee. （ C） Student-Librarian. （ D） Lawyer-Client. （ A） The foreign student needs to get credits of 24 semester hours. （ B） The foreign student needs to get at least 120 credits. （ C）

45、 The foreign student needs to get at least 120 credits plus thesis. （ D） The foreign student needs to get credits 0f24 semester hours plus 14 consecutive semesters. （ A） It focuses on the development of the student s ability for independent scholarly work in a particular field. （ B） It focuses on a

46、variety of fields of knowledge and emphasizes the development of the student s ability for independent research of all fields. （ C） It focuses on a specific field of knowledge and emphasizes the development of the student s ability of cooperation. （ D） Not mentioned. （ A） Students working on a docto

47、ral program with a Master s degree have ten consecutive semesters to complete the requirements. （ B） Students entering a graduate study have 14 consecutive semesters to complete the requirements. （ C） Students may continue their studies towards the doctoral degree after completing an M.A. or M.S. （

48、D） Students working on a doctoral program without a Master s degree have fourteen consecutive emesters. 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

49、you hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） She is selfish and cruel. （ B） She is kind and polite. （ C） She is proud and helpful. （ D） She is lonely and unhappy. （ A） Rent is within the budget of university students. （ B） Both room and board are often provided. （ C） Student housing is located on campus. （ D） The maintenance is usually handled by someone else. （ A） They may have to follow certain housing rules. （ B）