大学英语四级295及答案解析.doc

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1、大学英语四级 295及答案解析(总分：746.55，做题时间：130 分钟)一、Writing (30 minutes)(总题数：1，分数：30.00)1.For this part, you are allowed thirty minutes to write a composition on the topic: How to Help New Students with Their Problems? You should write at least 120 words according to the outline given below: 假设你是一位新入校的学生，你认为学校应

2、该如何帮助新生处理他们会面临的问题。请绐出你的建议。 （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 quickly double the efficiency

3、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. These two forces are leadin

4、g 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 fossil fuel economy While fo

5、ssil 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 oxides, the main source of urb

6、an 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. Global warmingThe carbon dioxide

7、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. Dependence-The United States, and

8、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 price. Advantages of the hydr

9、ogen 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 power, it is a completely cl

10、ean 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 environment. There is a perfect c

11、ycle-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 production-Hydrogen can be produced

12、 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 toward the hydrogen economy is ve

13、ry 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. Once both of these questions a

14、re 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. One big advantage of this proc

15、ess 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 carbon. Using a device called

16、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 using fossil fuel as the sour

17、ce 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 interesting thing about the first opt

18、ion 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 water, and generating that

19、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 coal or natural gas. All of tha

20、t 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 tidal power Co-generation H

21、ow 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, solutions to the hydrogen storage p

22、roblem 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. The main barrier to this m

23、ight 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 could develop quickly; that s

24、ort 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 fossil fuel economy are combining

25、 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 represent two major improvements ove

26、r 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 spill can pose a big problem t

27、o 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.NC.NG(5).In the United States

28、, 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 be stored. （分数：7.10）A.YB.NC.

29、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 hydrogen economy, the most o

30、bvious step we will take is _. （分数：7.10）_三、Listening Comprehens(总题数：1，分数：15.00)A.The wind has stopped, but its still snowing.B.The snow has stopped.C.Its still snowing and the wind is blowing.D.Both the snow and the wind have stopped.A.He will take a summer course.B.He will stay at home.C.He will re

31、main at school.D.He will visit some places.A.At home.B.On a farm.C.At a birthday party.D.In a restaurant.A.The man has just started talking to the woman.B.The man has just finished talking to the woman.C.The man and the woman are husband and wife.D.The man and the woman are indifferent to each other

32、.A.Cooler and drier.B.Cooler and rainier.C.Warmer and drier.D.Warmer and rainier.A.The train is crowded.B.The train is late.C.The train is empty.D.The train is on time.A.She misplaced class card for biology.B.She arrived for registration too early.C.She missed registration.D.The man cannot spell her

33、 name.A.In the restaurant.B.At the railway station.C.In the post office.D.At the airport.四、Section B(总题数：2，分数：10.00)A.Children Literature.B.American Literature.C.Medicine.D.Elementary Education.A.They find these stories interesting.B.They can learn how to write such stories.C.These stories are writt

34、en by a famous doctor.D.The stories are on their reading list.A.They are the same person.B.One is a doctor and the other is a writer.C.Both of them are teachers.D.They are from different departments.A.It is a book written only for classroom reading.B.It is a book on education.C.It has a vocabulary o

35、f only two hundred words.D.It was written by a child.A.Protection of intellectual property.B.To say “no“ to piracy.C.Luxury items and their prices.D.People and pirated products.A.It is illegal.B.It is bad.C.It is unfair.D.It is acceptable.A.Because he doesnt think it illegal to buy them.B.Because he

36、 thinks they are not sold for great profits.C.Because he thinks they are accessible to most people.D.Because he thinks they are as good as real things.A.To uphold his stand that there is reason in pirated stuff.B.To give a fact that “Ferraris“ is not for everyone.C.To present his argument that buyin

37、g pirated stuff is not illegal.D.To tell the truth that pirated luxury items make people feel good.A.He got his first bicycle in 1971.B.He got his first bicycle when he was seven.C.He got his first bicycle when he was at high schoolD.He got his first bicycle in 1992.A.No.1B.7thC.14thD.40thA.In 1992.

38、B.In 1993.C.In 1996.D.In 1997.A.4 times.B.5 times.C.6 times.D.7 times.A.Because London taxi drivers all have gone through a very tough training period to get a special taxi driving licence.B.Because London taxi drivers all are London natives.C.Because London drivers all are living in the corner of t

39、he Capital.D.Not given.A.Two years.B.Three years.C.Four years.D.Two to four years.A.He has to learn how to get a certain place in the shortest time.B.He has to learn how to please customers.C.He has to learn how to the most direct route to every single road and to every important building in London.

40、D.He has to learn how to go around the city on small motorbikes.A.Because learner drivers have to pay for their own expenses on the tests and the medical exam.B.Because learner drivers have to give money to the officers in the tests.C.Because the training period is too long.D.Because learner drivers

41、 cannot earn money during the training period.A.He was a tax collector.B.He was a government official.C.He was once a friend of the ruler.D.He was once a school teacher in India.A.To reward outstanding tax collectors.B.To declare new ways of collecting tax.C.To collect money from the persons invited

42、.D.To entertain those who had made great contributions to the government.A.They were excused from paying income tax.B.They were given some silver and gold coins by the ruler.C.They tried to collect more money than the ruler asked for.D.They enjoyed being invited to dinner at the rulers palace.六、Sect

43、ion C(总题数：1，分数：10.00)Richard Henry, An American physicist, is (36) 1a new in which important days could fall on the same day of the week year after year. Instead of the familiar Gregorian (罗马教皇的) 365-day year with one (37) 2day added every four years. The new (38) 3offers a 364-day year with a (39)

44、4week every five or six years. Richard Henry has taught physics and (40) 5courses in Johns Hopkins University for nearly thirty years. Although the (41) 6remains essentially the same, the homework is due on different dates each year and the exam dates changed, too. So, each year, he has to make up a

45、 different (42) 7for his students. He said to himself, I dont mind doing that because I have to do it. But then one year I said, Wait, Im a (43) 8astronomer. Let me see whether this is necessary or not. And quickly I discovered that it is not necessary at all. That is because, (44) 9. An astronomica

46、l year set by the motion of the earths rotation going a-round the sun is 365.2422 days long. And of course, 365 is not divisible by seven (45) 10. Each month in this revised year would have either 30 or 31 days, which means that eight months would be longer or shorter than they are now. (46) 11. （分数

47、：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)Vacations are what keep us going: fantasies of sunny, sandy beaches on rainy, gray days when the kids are bouncing off the walls; touring a quiet museum instead of listening to your boss barking in the next office; hiking a mountain rather than sitting in rush-hour traffic. But vacations, by their nature, are also a change an interruption of the familiar flow of people, places and routines. Thats why adults find travel exciting and why it can be hard on kids.