1、大学英语六级模拟试卷 216及答案与解析 一、 Part I Writing (30 minutes) 1 Directions: For this part, you are allowed thirty minutes to write a composition on the topic It Pays to Be Honest. You should write at least 150 words according to the outline given below in Chinese: 1. 当前社会存在许多不诚实的现象。 2. 诚实利人利己，做人应该诚实。 二、 Part
2、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 given in the passage; N
3、(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 Acid Rain What Is Acid Rain? “Acid rain“ is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid d
4、eposition, which has two parts: wet and dry. Wet deposition refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depends on many factors, including how acidic the water is, the chemistry
5、and buffering (隔离 ) capacity of the soils involved, and the types offish, trees, and other living things that rely on the water. Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition. The wind blows these acidic pa
6、rticles and gases onto buildings, cars, homes, and trees. Dry-deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acres to the acid rain, making the combination more acidic than the falling rain alone. How Do We
7、 Measure Acid Rain? Acid rain is measured using a scale called “pH“. The lower a substances pH, the more acidic it is. Pure water has a pH of 7.0. Normal rain is slightly acidic because carbon dioxide dissolves into it, so it has a pH of about 5.5. As of the year 2000, the most acidic rain falling i
8、n the U.S. has a pH of about 4.3. Effects of Acid Rain Acid rain causes acidification (酸化 ) of lakes and streams and contributes to damage of trees at high elevations (for example, red spruce trees above 2,000 feet) and many sensitive forest soils. In addition, acid rain accelerates the decay of bui
9、lding materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nations cultural heritage. Prior to failing to the Earth, SO2 and NOx gases and their particulate matter derivatives, sulfates and nitrates contribute to visibility degradation and harm public
10、 health. What Society Can Do About Deposition? There are several ways to reduce acid deposition, ranging from societal changes to individual action. Understand Acid Depositions Causes and Effects To understand acid depositions causes and effects and track changes in the environment, scientists from
11、EPA, state governments, and academies study acidification processes. They collect air and water samples and measure them for various characteristics like pH and chemical composition, and they research the effects of acid deposition on human-made materials such as marble and bronze. Finally, scientis
12、ts work to understand the effects of sulfur dioxide (SO2) and nitrogen oxides (NOx) the pollutants that cause acid deposition and fine particles on human health. To solve the acid rain problem, people need to understand how acid rain causes damage to the environment. They also need to understand wha
13、t changes could be made to the air pollution sources that cause the problem. The answers to these questions help leaders make better decisions about how to control air pollution and therefore how to reduce or even eliminate acid rain. Since there are many solutions to the acid rain problem, leaders
14、have a choice of which options or combinations of options arc best. The next section describes some of the steps that can be taken to reduce, or even eliminate, the acid deposition problem. Clean Up Smokestacks (烟囱 ) and Exhaust Pipes Almost all of the electricity that powers modem life comes from b
15、urning fossil fuels like coal, natural gas, and oil. Acid deposition is caused by two pollutants that are released into the atmosphere, or emitted, when these fuels are burned: sulfur dioxide (SO2) and nitrogen oxides (NOx). Coal accounts for most U.S. sulfur dioxide (SO2) emissions and a large port
16、ion of NOx emissions. Sulfur is present in coal as an impurity, and it reacts with air when the coal is burned to form SO2. In contrast, NOx is formed when any fossil fuel is burned. There are several options for reducing SO2 emissions, including using coal containing less sulfur, washing the coal,
17、and using devices called scrubbers to chemically remove the SO2 from the gases leaving the smokestack. Power plants can also switch fuels; for example burning natural gas creates much less SO2 than burning coal. Certain approaches will also have additional benefits of reducing other pollutants such
18、as mercury and carbon dioxide. Understanding these “co-benefits“ has become important in seeking cost-effective air pollution reduction strategies. Finally, power plants can use technologies that dont burn fossil fuels. Each of these options has its own costs and benefits, however; there is no singl
19、e universal solution. Use Alternative Energy Sources There are other sources of electricity besides fossil fuels. They include: nuclear power, hydropower, wind energy, geothermal energy, and solar energy. Of these, nuclear and hydropower are used most widely; wind, solar, and geothermal energy have
20、not yet been harnessed on a large scale in this country. There are also alternative energies available to power automobiles, including natural-gaspowered vehicles, battery-powered cars, fuel cells, and combinations of alternative and gasolinepowered vehicles. All sources of energy have environmental
21、 costs as well as benefits. Some types of energy are more expensive to produce than others, which means that not all Americans can afford all types of energy. Nuclear power, hydropower, and coal are the cheapest forms today, but changes in technologies and environmental regulations may shift that in
22、 the future. All of these factors must be weighed when deciding which energy source to use today and which to invest in for tomorrow. Restore a Damaged Environment Acid deposition penetrates deeply into the fabric of an ecosystem, changing the chemistry of the soil as well as the chemistry of the st
23、reams and narrowing, sometimes to nothing, the space where certain plants and animals can survive. Because there are so many changes, it takes many years for ecosystems to recover from acid deposition, even after emissions are reduced and the rain becomes normal again. For example, while the visibil
24、ity might improve within days, and small or chemical changes in streams improve within months, chronically acidified lakes, streams, forests, and soils can take years to decades or even centuries (in the case of soils) to heal. However, there are some things that people do to bring back lakes and st
25、reams more quickly. Limestone (石灰石 ) or lime (a naturally-occurring basic compound) can be added to acidic lakes to “cancel out“ the acidity. This process, called liming, has been used extensively in Norway and Sweden but is not used very often in the United States. Liming tends to be expensive, has
26、 to be done repeatedly to keep the water from returning to its acidic condition, and is considered a short-term remedy in only specific areas rather than an effort to reduce or prevent pollution. Furthermore, it does not solve the broader problems of changes in soil chemistry and forest health in th
27、e watershed, and does nothing to address visibility reductions, materials damage, and risk to human health. However, liming does often permit fish to remain in a lake, so it allows the native population to survive in place until emissions reductions reduce the amount of acid deposition in the area.
28、Look to the Future As emissions from the largest known sources of acid deposition-power plants and automobiles are reduced, EPA scientists and their colleagues must assess the reductions to make sure they are achieving the results Congress anticipated. If these assessments show that acid deposition
29、is still harming the environment, they may consider additional emissions reductions from sources that have already been controlled, or methods to reduce emissions from other sources. They may also invest in energy efficiency and alternative energy. Take Action as Individuals It may seem like there i
30、s not much that one individual can do to stop acid deposition. However, like many environmental problems, acid deposition is caused by the cumulative actions of millions of individual people. Therefore, each individual can also reduce their contribution to the problem and become part of the solution
31、. One of the first steps is to understand the problem and its solutions. Individuals can contribute directly by conserving energy, since energy production causes the largest portion of the acid deposition problem. For example, you can: Turn off lights, computers, and other appliances when youre not
32、using them. Use energy efficient appliances: lighting, air conditioners, heaters, refrigerators, washing machines, etc. Only use electric appliances when you need them. Keep your thermostat at 68F in the winter and 72F in the summer. You can mm it even lower in the winter and higher in the summer wh
33、en you are away from home. Insulate (隔热 ) your home as best you can. Carpool (合伙使用权用汽车 ), use public transportation, or better yet, walk or bicycle whenever possible. Buy vehicles with low NOx emissions, and maintain all vehicles well. Be well-informed. 2 The higher a substances pH, the more acidic
34、it is. （ A） Y （ B） N （ C） NG 3 Acid rain may damage trees, soils and accelerate the decay of buildings. （ A） Y （ B） N （ C） NG 4 If taking proper steps, we can eliminate acid deposition. （ A） Y （ B） N （ C） NG 5 To solve acid rain problems, we must have experts develop high technology. （ A） Y （ B） N （
35、 C） NG 6 A more precise term for acid rain is_, which has two parts: wet and dry. 7 The scale used to measure acid rain is called_. 8 The two pollutants that cause acid deposition are_and nitrogen oxides (NOx). 9 Among the alternative energy sources,_, and coal are the cheapest forms today. 10 In No
36、rway and Sweden, the process called_has been used extensively to “cancel out“ the acidity in acidic lakes. 11 Individuals can contribute directly to solving the problem of acid deposition by_. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the
37、 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 answer.
38、 （ A） 2. （ B） 3. （ C） 6. （ D） 9. （ A） In a theater. （ B） In a clinic. （ C） At a bank. （ D） In a plane. （ A） A kind of feeling. （ B） A kind of seasoning. （ C） The seafood banquet. （ D） Tom Markhams new house. （ A） He thinks the pants fit him at the waist. （ B） He thinks the pants are a little tight o
39、n the hips. （ C） He thinks the price is reasonable. （ D） He doesnt feel like buying the pants. （ A） To look for the lost textbook in the library. （ B） To call Lost-and-Found first before buying a new one. （ C） To buy a new textbook since the final exam is coming soon. （ D） To borrow a textbook on wh
40、ich therere notes taken already. （ A） The man bought the watch last Sunday. （ B） The manager can give money back to the man. （ C） The woman will speak to the manager about the matter. （ D） The waterproof watch was bought in the period of promotion. （ A） To go to the overseas-students housing office
41、for help. （ B） To check the list of the available apartment on the Internet. （ C） To see different landladies so as to find a satisfying apartment. （ D） To check out an apartment for his parents. （ A） The womans elderly aunt isnt easy-going. （ B） The womans elderly aunt hates noise but likes ketchup
42、. （ C） The woman had better adjust her attitude towards the matter. （ D） The woman had better send her aunt to some other place to live. （ A） Boss and secretary. （ B） Customer and salesman. （ C） Doctor and patient. （ D） Husband and wife. （ A） $15. （ B） $50. （ C） $35. （ D） $20. （ A） The woman has bou
43、ght a T-shirt as her husbands birthday present last month. （ B） The woman likes the dark color very much. （ C） The woman spends $35 to buy the presents for her husband and daughter （ D） The woman can rub and wring the silk when she washes it. （ A） It exists close to the surface of the Earth. （ B） It
44、 is a component of smog and a harmful substance. （ C） It is a kind of yellow gas. （ D） It is formed through a complex reaction. （ A） It hurts our eyes. （ B） It hurts our skin. （ C） It is harmful to our respiratory system. （ D） It can cause cancers. （ A） Spring. （ B） Summer. （ C） Autumn. （ D） Winter.
45、 （ A） Ozone is an extremely inactive gas. （ B） Ozone only exists in the upper atmosphere. （ C） Ground-level ozone is closely related to peoples health. （ D） Children breathe more air per pound of body weight than adults. Section B Directions: In this section, you will hear 3 short passages. At the e
46、nd 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） The mans professor. （ B） The mans roommate. （ C） A neighbor. （ D） The mans brothe
47、r. （ A） He is too sloppy. （ B） He borrows Colins things. （ C） He brings guests over to the apartment. （ D） He doesnt use the kitchen enough. （ A） Try to talk to Colin. （ B） Go home for a week. （ C） Wait till the end of this week. （ D） Have a room change immediately. （ A） Kings and queens, princes an
48、d princesses, and lords and ladies built castles in order to get more land. （ B） Around the outside of a castle, a moat was dug, which was often filled with water. （ C） A castle was built behind a thick and high stonewall, which was strong enough to stand the possible attack of enemies. （ D） If a dr
49、awbridge was pulled up, there was no way for people to enter the castle. （ A） They lived a luxurious life and their diet was very delicate. （ B） They lived a highly civilized court life. （ C） They lived a primitive life and their table manner was often rude. （ D） They lived a comparatively luxurious but not so civilized life. （ A） Castles structure and the eating habit in them. （ B） Castles structure and the people who lived in them. （ C） Castles structure and
