1、大学英语四级 42 及答案解析(总分：746.57，做题时间：130 分钟)一、Writing (30 minutes)(总题数：1，分数：30.00)1.Directions: For this part, you are allowed thirty minutes to write “An Eye-Witness Account of a Traffic Accident”. You should write at least 120 words according to the outline given below in Chinese: 假设你在某日某时地目击一起车祸，就此写一份见
2、证书。见证书须包括以下几点： 1. 车祸发生的时间及地点 2. 你所见到的车祸情况 3. 你对车祸原因的分析 （分数：30.00）_二、Reading Comprehensio(总题数：1，分数：71.00)THE HYDROGEN ECONOMY It seems like every day there is a new announcement in the news about automobiles powered by fuel cells. The promises are great, since fuel cells have the potential to very qu
3、ickly double the efficiency of cars while significantly reducing air pollution. At the same time, there have been news stories for decades about the problems associated With petroleum. Everything from oil spills to ozone(臭氧) alerts to global warming gets blamed on our dependence on fossil(化石) fuels.
4、 These two forces are leading the world toward what is broadly known as the hydrogen economy. If the predictions are true, over the next several decades we will all begin to see an amazing shift away from the fossil fuel economy we have today toward a much cleaner hydrogen future. Problems with the
5、fossil fuel economy While fossil fuels have played an important role in getting society to the point it is at today, there are four big problems that fossil fuels create: Air pollution-When cars burn gasoline, the internal combustion engine also produces: Carbon monoxide, a poisonous gas Nitrogen ox
6、ides, the main source of urban smog Unburned hydrocarbons, the main source of urban ozone Environmental pollution-The process of transporting and storing oil has a big impact on the environment whenever something goes wrong. An oil spill, pipeline explosion or well fire can create a huge mess. Globa
7、l warmingThe carbon dioxide coming out of every cars tailpipe is a greenhouse gas that is slowly raising the temperature of the planet. The ultimate effects are unknown, but it is a strong possibility that, eventually, there will be dramatic climate changes that affect everyone on the planet. Depend
8、ence-The United States, and most other Countries, cannot produce enough oil to meet demand, so they import it from oil-rich countries. That creates an economic dependence. When Middle East oil producers decide to raise the price of oil, the rest of the world has little choice but to pay the higher p
9、rice. Advantages of the hydrogen economy The hydrogen economy promises to eliminate all of the problems that the fossil fuel economy creates. Therefore, the advantages of the hydrogen economy include: The elimination of pollution caused by fossil fuels-When hydrogen is used in a fuel cell to create
10、power, it is a completely clean technology. The only byproduct is water. There are also no environmental dangers like oil spills to worry about with hydrogen. The elimination of greenhouse gases-If the hydrogen comes from the electrolysis of water, then hydrogen adds no greenhouse gases to the envir
11、onment. There is a perfect cycle-electrolysis produces hydrogen from water, and the hydrogen recombines with oxygen to create water and power in a fuel cell. The elimination of economic dependence-The elimination of oil means no dependence on the Middle East and its oil reserves. Distributed product
12、ion-Hydrogen can be produced anywhere that you have electricity and water. People can even produce it in their homes with relatively simple technology. The problems with the fossil fuel economy are so great, and the environmental advantages of the hydrogen economy so significant, that the push towar
13、d the hydrogen economy is very strong. Technological Hurdles(障碍) The big question with the hydrogen economy is, “Where does the hydrogen come from?“ After that comes the question of transporting, distributing and storing hydrogen. Hydrogen tends to be large and tricky in its natural gaseous form. On
14、ce both of these questions are answered in an economical way, the hydrogen economy will be in place. Where does the hydrogen come from? There are two possible sources for the hydrogen: Electrolysis of water-Using electricity, it is easy to split water molecules to create pure hydrogen and oxygen. On
15、e big advantage of this process is that you can do it anywhere. For example, you could have a box in your garage producing hydrogen from tap water, and you could fuel your car with that hydrogen. Reforming fossil fuels-Oil and natural, gas contain hydrocarbons-molecules consisting of hydrogen and ca
16、rbon. Using a device called a fuel processor or a reformer, you can split the hydrogen off the carbon in a hydrocarbon relatively easily and then use the hydrogen. You discard the leftover carbon to the atmosphere as carbon dioxide. The second option is, of course, slightly perverse(不正当的). You are u
17、sing fossil fuel as the source of hydrogen for the hydrogen economy. This approach reduces air pollution, but it doesnt solve either the greenhouse gas problem or the dependence problem. However, it may be a good temporary step to take during the transition(转变) to the hydrogen economy. The interesti
18、ng thing about the first option is that it is the core of the real hydrogen economy. To have a pure hydrogen economy, the hydrogen must be derived from renewable sources rather than fossil fuels so that we stop releasing carbon into the atmosphere. Having enough electricity to separate hydrogen from
19、 water, and generating that electricity without using fossil fuels, will be the biggest change that we see in creating the hydrogen economy. Where will the electricity for the electrolysis of water come from? Currently, about 68 percent of the electricity produced in the United States comes from coa
20、l or natural gas. All of that generating capacity will have to he replaced by renewable sources in the hydrogen economy. Right now there are several different ways to create electricity that do not use fossil fuels: Nuclear power Hydroelectric dams Solar cells Wind turbines Geothermal power Wave and
21、 tidal power Co-generation How do you store and transport the hydrogen? Hydrogen is a large gas of its kind, and it is not nearly as easy to work with as gasoline. Compressing the gas requires energy, and compressed hydrogen contains far less energy than the same volume of gasoline. However, solutio
22、ns to the hydrogen storage problem are surfacing. For example, hydrogen can be stored in a solid form in a chemical called sodium borohydride. Once the storage problem is solved and standardized, then a network of hydrogen stations and the transportation infrastructure will have to develop around it
23、. The main barrier to this might be the technological sorting-out process. Stations will not develop quickly until there is a storage technology that clearly dominates the marketplace. For instance, if all hydrogen-powered cars from all manufacturers used sodium borohydride, then a station network c
24、ould develop quickly; that sort of standardization is unlikely to happen rapidly, if history is any guide. Prospects for the future You will hear more and more about the hydrogen economy in the news in the Coming months, because the drumbeat is growing louder. The environmental problems of the fossi
25、l fuel economy are combining with breakthroughs(突破) in fuel-cell technology, and the pairing will allow us to take the first steps, The most obvious step we will see is the marketing of fuel-cell-powered vehicles. Although they will be powered initially by gasoline and reformers, fuel cells represen
26、t two major improvements over the internal combustion engine: They are about twice as efficient. They can significantly reduce air pollution in cities. （分数：71.00）(1).The passage gives a general description of the benefits and potential problems of a hydrogen economy. （分数：7.10）A.YB.NC.NG(2).An oil sp
27、ill can pose a big problem to the environment. （分数：7.10）A.YB.NC.NG(3).Compared with other major industrialized countries, the United States depends more heavily on oil import. （分数：7.10）A.YB.NC.NG(4).Even if you have electricity and water, you still cannot produce hydrogen everywhere. （分数：7.10）A.YB.N
28、C.NG(5).In the United States, most of the electricity is generated from coal or natural gas. （分数：7.10）A.YB.NC.NG(6).We must derive hydrogen from renewable sources with a view to a pure hydrogen economy. （分数：7.10）A.YB.NC.NG(7).So far, there seems to be no solution in sight as to how the hydrogen can
29、be stored. （分数：7.10）A.YB.NC.NG(8).Possible sources for the hydrogen are both electrolysis of water and _. （分数：7.10）_(9).If the storage problem is _ and _, a network of hydrogen stations and the transportation infrastructure will have to develop around it. （分数：7.10）_(10).Concerning the future of the
30、hydrogen economy, the most obvious step we will take is _. （分数：7.10）_三、Listening Comprehens(总题数：1，分数：15.00)A.No one can find a supermarket.B.He helps people find a supermarket here.C.He has no idea where to find a supermarket.D.His family lives in this city.A.In a library.B.In a bookstore.C.In a cla
31、ssroom.D.In the womans home.A.A doctor.B.A salesman.C.A pharmacist.D.A librarian.A.He has a better idea.B.He wants to be invited.C.It will depend on the weather.D.He is sure to go for an outing.A.Present a new book to the class.B.Read more than one book.C.Read the book more thoroughly.D.Read the boo
32、k to the class.A.Jane knows practically everyone.B.Jane knows Karl isnt hard to be happy.C.Karl didnt order the right thing.D.Jane always knows exactly what to say.A.He disagrees with the woman.B.He prefers not to argue about it.C.He shares the womans opinion.D.He wasnt able to live in the hotel.A.M
33、arcia looks good in everything.B.He knew someone who looked like Marcia.C.He wishes he had a coat like Marcias.D.Marcia should get a new coat.四、Section B(总题数：2，分数：10.00)A.The man wants to obtain an international drivers license that he can use both in the U.S. and in his country.B.The man wants to t
34、ake a drivers test to get an Arizona drivers license.C.The man wants to know whether he can use his international drivers license in Arizona.D.The man wants to fill out an application for an Arizona drivers license.A.Show his student ID and pay ten dollars.B.Use his international drivers license.C.T
35、ake a drivers test and apply for a limited license.D.Show proof of temporary residence.A.Less than one year.B.Four years.C.Five years.D.Ten years.A.Fill out an application.B.Go back to the university to get his ID.C.Go to see his friend.D.Take a written exam and an eye exam.A.In central London.B.Nea
36、r a police station.C.By the tube station.D.On a side street.A.Green.B.Red.C.White.D.Black.A.It was stolen.B.It was given a ticket.C.She couldnt find it.D.She found it towed away by the police.A.She went to a police station nearby.B.She talked to a policeman on patrol.C.She took a taxi as a policeman
37、 advised her to do.D.She telephoned the police for help.A.They havent devoted as much energy to medicine as to space travel.B.There are too many kinds of cold viruses for them to identify.C.It is not economical to find a cure for each type of cold.D.They believe people can recover without treatment.
38、A.They reveal the seriousness of the problem.B.They indicate how fast the virus spreads.C.They tell us what kind of medicine to take.D.They show our body is fighting the virus.A.It actually does more harm than good.B.It causes damage to some organs of our body.C.It works better when combined with ot
39、her remedies.D.It helps us to recover much sooner.A.It can be used by farmers to protect large buildings.B.It was brought to the northern USA by Asian farmers.C.It has done more harm than good in the southern USA.D.It was introduced into the USA to kill harmful weeds.A.People will have to rely on ku
40、dzu for a living.B.They will soon be overgrown with kudzu.C.They will become too hard to plough.D.People will find it hard to protect the soil.A.The farmers there have brought it under control.B.The factories there have found a good use for it.C.The climate there is unfavorable to its growth.D.The s
41、oil there is not so suitable for the plant.A.Three minutes.B.Two Minutes.C.One minutes.D.Five minutes.A.To win a competition.B.To break a record.C.To deliver the news of victory.D.To win the first prize.A.Because he surpasses the fellow runners.B.Because he still can run.C.Because he overcomes fatig
42、ue with his will-power.D.Because he wins the prize.六、Section C(总题数：1，分数：10.00)Some of the notebooks George Washington kept as a young man are still in (36) 1. They show that he was learning Latin, was very interested in the basics of good behavior in society, and was reading English (37) 2. At schoo
43、l he seemed only to have been interested in (38) 3. In fact his formal education was (39) 4 brief for a gentleman, and incomplete. For unlike other young Virginian gentlemen of that day, he did not go to the College of William and Mary in the Virginian (40) 5 of Williamsburg. In terms of formal (41)
44、 6 then, Washington (42) 7 sharply with some other early American Presidents such as John Adams, Thomas Jefferson and James Madison. In later years, Washington probably regretted his lack of (43) 8 . (44) 9, or on any subject that had not to do with everyday, practical matters. (45) 10, he did not v
45、isit the country he admired so much. (46) 11. （分数：10.00）填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_七、Reading Comprehensio(总题数：2，分数：355.00)The large American energy service company, Enron, failed two years ago. It had been the seventh largest company in the United St
46、ates. More than twenty people have been charged with financial crimes related to the companys hidden debt, inflated (夸大的) profits and accounting risks. On January 22nd, Enron s former chief accounting officer faced charges of helping Enron cheat investors and others. Richard Causey said he is not gu
47、ilty. He says he believed all of Enrons financial records were correct. He says he followed rules called the Generally Accepted Accounting Standards. The government says Mr. Causey used his knowledge of accounting to make Enron look profitable. The government says Mr. Causey sought to gain from his actions by causing the price of Enron stock to increase. The government has charged Mr. Causey with planning businesses related to Enron, called partnerships. Enron used financial exchanges with partnerships to hide big financial losses. The government says these exchanges do n
