1、大学英语六级模拟试卷 345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 letter to ask for some information about an international conference held in your city. You should write at least 150 words following the outline given below. 有一个会议在你所在的城市召开，你想去参加。给
2、会议的组织者写一封信。说一下你想参加的原因，并简单介绍一下自己。并请他提供一些会议的相关登信息。 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 state
3、ment 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 extreme weather and say there is
4、 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 been as high as 27 and as low as
5、 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 greenhouse effect refers to the role
6、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 that are changing little and it play
7、s almost no role in modem human-induced greenhouse warming. Other greenhouse gases include carbon dioxide, methane (甲烷 ) and nitrous (含氮的 ) oxide, which are released by modern industry, agriculture and the burning of fossil fuels. Their concentration in the atmosphere is increasing the concentration
8、 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 century and show that the global a
9、verage 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 records show Arctic sea-ice has thinned
10、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 atmosphere). How Much Will Temperature
11、s 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, particularly large bodies of water
12、 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 an estimated 7m rise in sea level
13、. 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 frequent. Scientists predict more
14、 rainfall overall, but say the risk of thought 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 ere difficult to predict. What Will the Effects
15、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 suffer most. Plant and animal extinc
16、tions 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-home disease and malnutrition. What Dont We Know? We dont know exactly what proportion of the observed warm
17、ing 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 mason why there is such uncertainty in projections of temperature incr
18、ease. 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 hake more carbon dioxide from the atmosphere as
19、 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 camps: -those who maintain temperat
20、ures 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, there is a growing scientific consensus
21、 (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 human activities. The report, from the f
22、ederal 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 the report say better data is badly nee
23、ded. 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 been used by “climate skeptics“ as pro
24、of 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 Ire rising. This means, it says, that the impact of human activities upon the global climate is clear. “The observed patterns of
25、 change over the past 50 years cannot be explained lay 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 still need resolving. Globally, the report
26、 concludes, tropospheric temperatures have risen by 0.10 and 0.20 per decade since 1979, when satellite dam 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 or less than the surface.“ Peter Thorne,
27、 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 are very noisy. From one day to the nex
28、t, the temperature can change by 10C, 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 margin of error. Additionally, the majo
29、rity 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 support for the concept of human-induced cl
30、imate 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. Satellites sense the “average“ temperat
31、ure 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 poor. Weather balloons (or radiosondes) ta
32、ke real-time measurements as they ascend, but scientists can never assess instruments afierwards; 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 recommendations for the kind of infrastructure
33、 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 satellites overlap so instruments can be cross
34、-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 scientific picture and providing hatter data
35、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 in surface temperatures and those in t
36、he 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 to the WHO, increases in malaria, water
37、-borne disease and malnutrition could threaten _. 8 The release of large quantifies 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 predict more warming in the troposphere than
38、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 8 short conversations and 2 long conver
39、sations. 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 t
40、he best answer. （ A） Mary is worthy of the prize. （ B） Mary has granted the prize. （ C） Mary fails in the speech contest. （ D） The man doesnt think Mary deserves the prize. （ A） Driving a car. （ B） Taking a taxi. （ C） Taking a train. （ D） Going by subway. （ A） He dislikes museums and galleries. （ B）
41、 He does not care about the weather. （ C） Going to the beach is the best choice. （ D） He doesnt want to go to Washington. （ A） She wants to live in the suburbs. （ B） She is offended by her naughty children. （ C） She disagrees with father. （ D） She turns a deaf ear to her husbands words. （ A） Call he
42、r after five. （ B） Make calls from her phone. （ C） Go to the meeting with her. （ D） Fix his phone. （ A） Husband and wife. （ B） Teacher and student. （ C） Policeman and driver, （ D） Mother and son. （ A） At the library. （ B） At the airport. （ C） At the post office. （ D） At the teachers office. （ A） He
43、is good at drawing pictures. （ B） He likes pictures very much. （ C） He likes visiting the art museum very much. （ D） He thinks the art museum is a very quiet place. （ A） He is a professional electrician. （ B） He possesses a basic knowledge of electricity. （ C） He knows nothing about electricity. （ D
44、） Electricity is his major. （ A） To wire her office. （ B） To fix the transformer. （ C） To wire her building. （ D） To fix the wires. （ A） The trans former. （ B） The battery. （ C） The fuses. （ D） The wires. （ A） Its next to Pueblo. （ B） Its in the southwest of the U.S. （ C） Its a city of India. （ D） I
45、ts outside the city Pueblo. （ A） Stone jewelry. （ B） Beautiful stone: （ C） Arts and crafts. （ D） Amazing paintings. （ A） Taos Pueblo. （ B） Apache. （ C） Navajo. （ D） Ute. （ A） For almost a thousand years. （ B） For a few decades. （ C） For a century. （ D） For several years. Section B Directions: In thi
46、s 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 from the four choices marked A, B, C and D. （ A） British, （ B） Americans. （ C）
47、Germans. （ D） Japanese. （ A） Entirely effective. （ B） Totally incorrect. （ C） A complete failure. （ D） Quite difficult （ A） Have a greater sense of duty. （ B） Can get higher pay. （ C） Can avoid working hard. （ D） Can avoid busy traffic. （ A） Winter in Alaska. （ B） The brave Alaskan people. （ C） Alas
48、kan transportation today. （ D） A dog sled race. （ A） Every year in March. （ B） Every other year, （ C） From two to three weeks. （ D） The winter of 1925. （ A） Winning. （ B） Finding gold. （ C） Just to finish. （ D） Being able to participate. （ A） To interest students in a career in counseling. （ B） To r
49、ecruit counselors to work in the placement office. （ C） To inform students of a university program. （ D） To convince local merchants to hire college students. （ A） A job listing. （ B） A resume. （ C） A permission slip. （ D） Their salary requirements. （ A） Refine their interviewing techniques. （ B） Arrange their work schedules. （ C） Select appropriate courses. （ D） Write cover letters. （ A） They pay the same wage. （ B） They involve working outdoors. （ C） They can be substituted for c
