大学六级-515及答案解析.doc

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1、大学六级-515 及答案解析(总分：703.00，做题时间：90 分钟)一、BPart Writing(总题数：1，分数：106.00)1.1. 近来移动 QQ、移动飞信等通信方式在大学生中十分流行 2. 这通信方式有许多优点 3. 我的观点 BThe Popularity of Instant Messaging Technologies/B（分数：106.00）_二、BPart Reading (总题数：1，分数：70.00)BNatural-gas Vehicles/BKermit the Frog once said,“ Its not that easy being green. “

2、Although he wasnt referring to cars, his observation seems particularly appropriate for the auto industry today: designing, developing and marketing “green“ cars has not been an easy task, which is why gasoline-powered vehicles still rule the world and fossil fuels still account for almost 75 percen

3、t of the worlds energy consumption. As gasoline soar and concern over harmful emission mounts, however, cars that run on alternate fuel sources will become increasingly important. A natural-gas vehicle, or NGV, is the perfect example of such a car - its fuel-efficient, environmentally friendly and o

4、ffers a relatively low cost of ownership. Natural gas basicsThe word“ gas“ is a confusing term because it is used to describe many different substances that are similar but not exactly the same. For example, the“ gas“ you put in your car is gasoline, one component of crude oil, or petroleum. Petrole

5、um is a dark, sticky liquid mixture of compounds formed underground by the decay of ancient marine animals.Natural gas also comes from the decay of ancient organisms, but it naturally takes a gaseous form instead of a liquid form. Natural gas commonly occurs in association with crude oil. It is deri

6、ved from both land plants and aquatic (水生的) organic matter and forms above or below oil deposits. It is often dissolved in crude oil at the high pressures existing in a reservoir. There are also reservoirs of natural gas, known as non-associated gas, that contain only gas and no oil.Natural gas cons

7、ists primarily of methane (沼气) and other hydrocarbon gases. Hydrocarbons are organic compounds composed only of the elements carbon and hydrogen. The hydrocarbons in natural gas are called saturated hydrocarbons (饱和烃) because they contain hydrogen and carbon bound together by single bonds.Like gasol

8、ine, natural gas is combustible (易燃的) ,which means it can be used in a combustion engine like gasoline. But cars that could burn natural gas didnt appear on the scene until the 1930s. BFrom field to ford/BWe extract natural gas trapped in underground reservoirs by drilling wells into the earth. A mo

9、dem well, equipped with diamond-studded drill bits, can drill to depths approaching 25,000 feet.Throughout the 19th century, the use of natural gas remained localized because there was no way to transport large quantities of gas over long distances. In 1890, the invention of a leakproof pipeline cou

10、pling made it possible to transport gas miles from the source. Improvements in pipeline technology continued over the next two decades until long-distance gas transmission became practical. From 1927 to 1931, laborers constructed more than 10 major natural gas transmission systems in the United Stat

11、es, making natural gas a viable energy source for many applications. The oil shortages of the late 1960s and early 1970s brought renewed interest in natural gas as a fuel source, especially for automobiles.Today, owners of natural-gas vehicles can fill up their cars at one of 1,300 fueling stations

12、located in the United States. Honda also offers a personal natural gas pump to people who purchase its natural-gas-powered Civic. The pump uses a homes existing natural gas lines and can be installed for500 to 1,500.BNatural-gas vehicle design/BNatural-gas vehicles use the same basic principles as g

13、asoline-powered vehicles. In other words, the fuel ( natural gas in this case) is mixed with air in the cylinder of a four-stroke engine and then ignited by a spark plug to move a piston (活塞) up and down. Although there are some differences between natural gas and gasoline in terms of flammability a

14、nd ignition temperatures, NGVs themselves operate on the same fundamental concepts as gasoline-powered vehicles.Still, some modifications are required to make an NGV work efficiently. These changes are primarily in the fuel storage tank, the engine and the chassis (底盘).BAdvantages/BThe biggest advan

15、tage of NGVs is that they reduce environmentally harmful emissions. Natural-gas vehicles can achieve up to a 93 percent reduction in carbon monoxide emissions, 33 percent reduction in emissions of various oxides of nitrogen and a 50 percent reduction in reactive hydrocarbons when compared to gasolin

16、e vehicles. NGVs also rate higher in particulate matter 10 (PM10) emissions. PM10 particles transport and deposit toxic materials through the air. NGVs that operate in diesel applications can reduce PM10 emissions by a factor of 10.Natural-gas vehicles also offer these benefits:NGVs are safer. The f

17、uel storage tanks on an NGV are thicker and stronger than gasoline or diesel tanks. There has not been an NGV fuel-tank rupture in more than two years in the United States.Natural gas costs are lower than gasoline. On average, natural gas costs one-third less than gasoline at the pump.Natural gas is

18、 convenient and abundant.-A well-established, pipeline infrastructure exists in the United States to deliver natural gas to almost every urban area and most suburban areas. There are more than 1,300 NGV fueling stations in the United States, and more are being added every day.Natural gas prices have

19、 exhibited significant stability compared to oil prices. Historically, natural gas prices have exhibited significant price stability compared to the prices of petroleum-based fuels. This stability makes it easier to plan accurately for long-term costs.NGVs have lower maintenance costs. Because natur

20、al gas burns so cleanly, it results in less wear and tear on the engine and extends the time between tune-ups and oil changes.BDisadvantages/BOne of the biggest complaints about NGVs is that they arent as roomy as gasoline cars. This is because NGVs have to give up precious cargo and trunk space to

21、accommodate the fuel storage cylinders. Not only that, these cylinders can be expensive to design and build - a contributing factor to the higher overall costs of a natural-gas vehicle compared to a gasoline-powered car.Another drawback is the limited driving range of NGVs, which is typically about

22、half that of a gasoline-powered vehicle. For example, Hondas natural gas Civic, the Civic GX, can go up to 220 miles without refueling. A typical gasoline-powered Civic can go approximately 350 miles without refueling. If a dedicated NGV ran out of fuel on the road, it would have to be towed to the

23、owners home or to a local natural gas refueling station, which might be harder to find than a “regular“ gas station.Finally, it should be noted that natural gas, like gasoline, is a fossil fuel and cannot be considered a renewable resource. While natural gas reserves in the United States are still c

24、onsiderable, they are not inexhaustible. Some predict that there are enough natural gas reserves remaining to last another 67.1 years, assuming that the 2003 level of production continues.（分数：70.00）(1).The gasoline-powered vehicles are prevalent as a result of _.（分数：7.00）A.comparatively low price of

25、 fossil fuelsB.reducing less harmful emissionsC.difficult tasks to design, develop and sale “green“ carsD.high fuel efficiency and protecting environment(2).What is the principal constituent of natural gas?（分数：7.00）A.Carbon and hydrogen.B.Methane and other hydrocarbon gases.C.Saturated hydrocarbons.

26、D.Non-associated gas.(3).The first car that could use natural gas as power in the combustion engine emerged in the history came out in _.（分数：7.00）A.the 19th centuryB.the 1930sC.the late 1960sD.the early 1970s(4).Why did people reconsider to make natural gas as a fuel source in the late 1960s and ear

27、ly 1970s?（分数：7.00）A.Because the price of gasoline was high.B.Because natural-gas vehicles are much faster than other vehicles.C.Because people made much account of environmental protection.D.Because it was short of oil.(5).In the United States, the fueling stations offering for filling natural gas h

28、ave reached to _.（分数：7.00）A.1,300B.500C.1,500D.2,500(6).The piston of a natural-gas vehicle moves up and down by the power of _.（分数：7.00）A.the spark plugB.the four-stroke engineC.the air in the cylinderD.the heat of natural-gas burning(7).Compared to gasoline-powered cars, the natural-gas vehicles p

29、ossess the unparalleled benefit of _.（分数：7.00）A.reduction in carbon monoxide emissionsB.reduction in emissions of oxides of nitrogenC.reduction in particulate matter 10D.reduction in environmentally harmful emissions(8).Natural gas burns so cleanly that the owners of the natural-gas vehicles have _.

30、（分数：7.00）填空项 1:_(9).NGVs arent as roomy as gasoline cars because they have to give up cargo and trunk space to accommodate _.（分数：7.00）填空项 1:_(10).Both natural gas and gasoline can not be considered renewable resources, because they are _.（分数：7.00）填空项 1:_三、BPart Listenin(总题数：3，分数：105.00)BQuestions 11

31、 to 18 are based on the conversation you have just heard./B（分数：56.00）A.The bus stop.B.The bad weather:C.The late bus.D.The traffic jam.A.A scientist.B.A weather reporter.C.A farmer.D.A worker.A.Its cloudy.B.It drizzles.C.It showers.D.It rains heavily.A.Great but tiring.B.Relaxing and memorable.C.Uns

32、atisfactory and exhausting.D.Exhausting but worthwhile.A.Ms Reed is going to Sydney on April 17th.B.Mr. Farnsworth is going to Sydney on flight 430.C.The flight leaves at 3:20 p. m.D.They are talking at the ticket office.A.Go shopping.B.Cook meals.C.Eat out.D.Buy a refrigerator.A.Three days ago.B.Fo

33、ur days ago.C.Five days ago.D.Six days ago.A.The mans clock was broken.B.The woman worked late yesterday.C.The man will help the woman with her work.D.The man doesnt believe the womans words.BQuestions 19 to 21 are based on the conversation you have just heard./B（分数：21.00）A.Communication means perso

34、n-to-person talking.B.Communication means emails and letters between colleagues.C.Communication means interactions between people.D.Communication means understanding between employees and clients.A.Its the most important part of communication.B.Its the only way to make an employee look professional.

35、C.Its vital to have good communication between colleagues.D.Its helpful to make a good impression on clients.A.Employees would perform the best if they have good communication with employers.B.Career success depends on how an employee develops his job skills.C.Companies hold social events only to he

36、lp employee build good private relationships.D.Miscommunication shall affect the growth of a company.Questions 22 to 25 are based on the conversation you have just heard.（分数：28.00）A.Spending more hours on the Internet.B.Spending fewer hours on the Internet.C.Their brighter expectations not being met

37、.D.Their bad state of being on the Internet.A.The Net is not healthy for people.B.The Net does not help with peoples communication.C.The Net is healthier than TV.D.The Net does no good to peoples psychological well-being.A.Because people give too much time to the Internet.B.Because people have more

38、friends on the Internet.C.Because people have less face-to-face conversations than before.D.Because people stay at home longer than before.A.The fast-developing technology.B.The increasing information and communication via the Net.C.The way how people make use of the Internet.D.The people who design

39、 different applications.四、BSection B/B(总题数：3，分数：70.00)BPassage OneQuestions 26 to 28 are based on the passage you have just heard./B（分数：21.00）A.It locates in the mountains.B.It is 5,000 feet above the sea level.C.There are about 4,500 residents in this town.D.It experienced a fire 7 years ago.A.Seve

40、nty percent.B.Eighty percent.C.Ninety percent.D.Ninety-five percentA.She has the ability to afford only one trees removal.B.She doesnt want her trees to be removed.C.She will apply for the state and federal loans.D.She thinks that the planners are inconsiderate.BPassage TwoQuestions 29 to 31 are bas

41、ed on the passage you have just heard./B（分数：21.00）A.Because this will help them catch criminals.B.Because this will help them control the crime rate.C.Because this will help them reduce the number of lawsuits.D.Because this will help them save much manpower and time.A.Five million dollars.B.Forty th

42、ousand dollars.C.One million dollars.D.Fifty thousand dollars.A.Most of them like it.B.Most of them hate it.C.Most of them doubt its necessity.D.Most of them doubt its feasibility.BPassage ThreeQuestions 32 to 35 are based on the passage you have just heard./B（分数：28.00）A.He only wants to change his

43、daughters grade.B.He wants to have the teacher apologize to his daughter.C.He only asks for compensation for emotional damages.D.He wants to change the grade and compensation.A.The Swim team.B.The Chinese chess club.C.The Girl Scouts.D.The church choir.A.She is 26 years old.B.She is Virginias econom

44、ics teacher.C.This is the first year of her teaching career.D.Few of her friends are African-Americans.A.He supports the student.B.He supports the teacher.C.He will keep neutrality.D.He hasnt shown his attitude.五、BSection C/B(总题数：1，分数：77.00)The American idea of respecting human rights came from seve

45、ral sources. First, the colonists had been U(36) /U. of their rights in the Old World. They realized that peoples rights must be U(37) /U. Moreover, the Bible and literature from Greece and Rome taught that people are born with basic rights. As a result, the U. S. Constitution included 10 U(38) /U t

46、o guarantee citizens basic rights. This “Bill of Rights” promised freedom of religion, freedom of speech and of the press, the right to bear arms and the right to a U(39) /U trial.Throughout American history, the belief in U(40) /U human rights has influenced government policies and laws. Slavery U(

47、41) /U argued that even slaves had rights as human beings. Finally, after the Civil War, slavery was U(42) /U. As industries developed, many people protested the poor working conditions. Eventually, laws were passed U(43) /U workers fair wages and working hours and prohibiting child labor. The Civil

48、 Rights Movement used human rights arguments in the fight against discrimination.Human rights have become a global concern. U(44) /U. Three years later, the UN adopted the Universal Declaration of Human Rights. U(45) /U. Later, groups like Amnesty International were formed to keep an eye out for human rights abuses wherever they occur.Most nations in the world today would agree that human beings have basic rights. Of course, different countries have different perspectives about the