英语六级听力考试预测模拟练习10

[00:00.00]Listening Comprehension  (20 minutes)

[00:-1.00]Section A

[00:-2.00]Directions:In this section,you will hear 10 short conversations.At the end of each conversation,a question will be asked about what was said.Both the conversation and the question 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.Then mark the corresponding letter on the Answer Sheet with a single line through the centre.

[00:-3.00]1.Q:What is the woman going to buy for herself?  A.She does not say.  B.Some wine.  C.Blue skirts and wine.  D.Some colorful dresses.

[00:16.33]2.Q:How do the man and woman feel about products made nowadays?  A.Satisfied with their price.  B.Displeased 1 with the quality.  C.Dissatisfied with their technology.  D.Happy with the modern mass-production techniques.

[00:33.88]3.Q:What is Dr.Cahill?  A.He is a dentist.  B.He's a physician.  C.He's a surgeon.  D.He's a chemist.

[00:53.92]4.Q:How far must the man walk to get to the Bank?  A.Two blocks.  B.Three blocks.  C.Four blocks.  D.Five blocks.

[01:14.69]5.Q:What can we learn from the conversation?  A.He cannot speak to his family.  B.He is living abroad.  C.His family is ill.  D.He is not worried at all.

[01:28.12]6.Q:What can we learn from the conversation?  A.The man dialed a wrong number.  B.John Black is out.  C.John Black has not come.  D.The woman is John Black's secretary.

[01:40.94]7.Q:What does the woman mean?  A.She prefers the stadium.  B.She agrees with the man.  C.The light is not bright enough.  D.The dining hall is not large enough.

[01:53.17]8.Q:What does the man mean?  A.He did not expect there would be so many books.  B.Five books are a lot to borrow from the library.  C.He is not sure she counted all her books.  D.She has reminded him that he also has some books to return.

[02:07.40]9.Q:What does the woman mean?  A.All the students would like a formal ball.  B.Raising the money will be hard.  C.The festival will begin the year nicely.  D.The club needs some sports as well.

[02:19.63]10.Q:What is the woman's opinion?  A.She feels the Andersons did a good thing.  B.She does not think they should move.  C.She thinks it is unwise to buy stocks.  D.She thinks it is better to invest later.

[02:18.63]Section B

[02:17.63]Compound Dictation

[02:16.63]Directions:In this section,you will hear a passage three times.When the passage is read for the first time,you should listen carefully for its general idea.Then listen to the passage again.When the passage is read for the second time,you are required to fill in the blanks numbered from S1 to S7 with the exact words you have just heard.For blanks numbered from S8 to S10 you are required to fill in the missing information.You can either use the exact words you have just heard or write down the main points in your own words.Finally,when the passage is read for the third time,you should check what you have written.

[02:29.35]Never before have so many people applied 3 such abstract (S1)_to so great a variety of problems.To meet the demands of industry,technology,and other sciences,mathematicians 4 have had to invent new(S2)_of mathematics and expand old ones.They have built a superstructure of fresh ideas that people trained in the(S3)_branches of the subject would hardly recognize as mathematics at all.(S4)_mathematicians have been grappling successfully with the world's problems at a time,curiously enough,when pure mathematicians seem almost to have lost touch with the(S5)_world.Mathematics has always been abstract,but pure mathematicians are pushing abstraction to new limits.To them mathematics is an art they(S6)_for art's sake,and they don't much care whether it will ever have any(S7)_use.(S8)_By applying its concepts to worldly problems,the mathematicians can often(S9)_.Celestial 5 mechanics,for example,enables astronomers(S10)_.

[02:28.35]Reading Comprehension  (35 Minutes)

[02:27.35]Directions:There are 4 passage in this part.Each passage is followed by some questions or unfinished statements.For each of them there are four choices marked [A],[B],[C],[D].You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre.

[02:26.35]Passage One

[02:25.35]Questions 11 to 15 are based on the following passage:

[02:24.35]The judgment 6 that cigarette smoking is hazardous 7 to health is the result of more than 30 years of research carried on by hundreds of scientists in this country and abroad.The conclusion that cigarette smoking is a significant health hazard is supported by every medical and health agency in the world which is known to have expressed an opinion on the matter.While cigarette smokers 9 tend to have higher death rates than nonsmokers,80 of the excess deaths associated with this habit are caused by three major disease.They are lung cancer,coronary heart disease,and emphysema.Lung cancer was a rare disease 50 years ago.Today,it is estimated that 60,000 men and woman per year in the U.S.A will die of this disease.Among men it is the most common cause of death from cancer.Cigarette smoking is the major cause of lung cancer.Although chronic 10 irritation 11 from certain chemical substances,radiation,viruses,occupational hazards,air pollution,and other environmental factors have been implicated 12 in this disease,they are of small importance compared with cigarette smoking.To those who smoke,however,they can be important in increasing the risks still further.Approximately 90 percent of all primary cancer cases occur in people who smoke cigarettes.Laboratory studies have isolated 13 from tobacco smoke a number of chemical compounds that can cause cancer.In addition,there are elements in smoke that interact with other compounds to promote cancer production.Millions of tiny,rhythmically moving hairs,called cilia protect the delicate tissue of the air tubes by propelling foreign matter,such as dust or pollen,toward the throat where it can be removed.Cigarette smoke paralyzes the cilia and inhibits 14 the work of cells that assist in cleaning the lungs.Thus the cancer-causing and cancer-promoting compounds can accumulate on the lining 15 of the bronchial tubes,where most cases of human lung cancer originate.These factors explain,in part,why the risk of developing lung cancer increases with the length of time the individual has smoked,the number of cigarettes he smokes per day,the depth of his inhalation,and the level of the tar 2 in the brand of cigatettes he uses.The risk of developing lung cancer increases further if a smoker 8 is exposed to certain occupational hazards.Studies show that asbestos workers who smoke have a risk 92 times higher than nonsmokers of the same age.

[02:23.35]11.Lung cancer was a rare disease 50 years ago because_.  A.air pollution was not a problem  B.people did not smoke as much as they do today  C.cigarettes did not contain harmful substances  D.people refused to smoke

[02:22.35]12.Studies show that asbestos fiber_.  A.cleans the cilia of the breathing passages  B.cause pneumonia 16 in factory workers  C.contributes to the development of lung cancer  D.has no effect on people's health

[02:21.35]13.According to the passage,heavy smoking can cause_.  A.heart attack  B.an ulcer 17  C.a stroke  D.a bad cold

[02:20.35]14.The author implies that_.  A.some viruses are caused by smoking  B.the desire to smoke is inherited  C.some experts will not admit that smoking is dangerous  D.nonsmokers sometimes develop lung cancer

[02:19.35]15.The reader can conclude that_.  A.smoking is harmful to health  B.smoking is a controversial subject  C.some experts will not admit that smoking is dangerous  D.nonsmokers tend to have higher death rates than smokers

[02:18.35]Passage Two

[02:17.35]Questions 16 to 20 are based on the following passage.

[02:16.35]Why does the Foundation concentrate its support on basic rather than applied research?Basic research is the very heart of science,and its cumulative 18 product is the capital of scientific progress,a capital that must be constantly increased as the demands upon it rise.The goal of basic research is understanding,for its own sake.Understanding of the structure of the atom or the nerve cell,the explosion of a spiral nebula 19 or the distribution of cosmic dust,the cause of earthquakes and droughts,or of man as a behaving creature and of the social forces that are created whenever two or more human beings come into contact with one another-the scope is staggering,but the commitment to truth is the same.If the commitment were to a particular result,conflicting evidence might be overlooked or,with the best will in the world,simply not appreciated.Moreover,the practical applications of basic research frequently cannot be anticipated.When Roentgen,the physicist,discovered Xrays,he had no idea of their usefulness of medicine.Applied research,undertaken to solve specific practical problems,has an immediate 20 attractiveness because the results can be seen and enjoyed.For practical reasons,the sums spent on applied research in any country always far exceed those for research,and the proportions are more unequal in the less developed countries.Leaving aside the funds devoted 21 to research by industry-which is naturally far more concerned with applied aspects because these increase profits quickly the funds the U.S.Government allots 22 to basic research currently amount to about 7 percent of its over-all research and development funds.Unless adequate safeguards are provided,applied research invariably tends to drive out basic.Then,as Dr.Waterman has pointed 23 out,"Development will inevitably 24 be undertaken prematurely,career incentives 25 will gravitate strongly toward applied science,and the opportunities for making major scientific discoveries will be lost.Unfortunately,pressures to emphasize new developments,without corresponding emphasize upon science...tend to degrade the quality of the nation's technology in the long run,rather than to improve it."

[02:15.35]16.The title below that best expresses the ideas of this passage is_.  A.Foundation Funds  B.Roentgen's Ignorance of X-rays  C.The Attractiveness of Applied Research  D.Basic Research vs.Applied Research

[02:14.35]17.Industry is primarily interesed in applied research because it_.  A.provides better understanding  B.is frowned upon by the Foundation  C.offers immediate profit  D.drives out basic research

[02:13.35]18.Basic research is vital because_.  A.it leads to results that can appreciated  B.It is driven out by applied research  C.it provides the basis for scientific progress  D.its results cannot be anticiped

[02:12.35]19.The federal governemnt_.  A.encourages basic research  B.devotes more than 90% of its research and developments funds to applied research  C.spends far more on applied research than on military problems  D.opposes the Foundation's grants to basic research

[02:11.35]20.Less developed countries_.  A. spend little on research  B.realize that progress depends on basic research  C.encourage their career scientists to experiment  D.devote less than 7% of their scientific budget to basic research.

[02:10.35]Passage Three

[02:09.35]Questions 21 to 25 are based on the following passage.

[02:08.35]Everyone has a moment in history which belongs particularly to him.It is the moment when his emotions achieve their most powerful sway over him,and afterward 26 when you say to this person"the world today"or"life"or "reality"he will assume that you mean this moment,even if it is 50 years past.The world,through his unleashed 27 emotions,imprinted itself upon him,and he carries the stamp of that passing moment forever.For me,this moment-4 years in a moment in history-was the war.The war was and is reality for me.I still instinctively 28 live and think in its atmosphere.These are some of its characteristics:Franklin Delano Roosevelt is the President of the United States,and he always has been.The other two eternal world leadres are Winston Churchill and Joseph Stalin.America is not,never has been,and never will be what the song and poems call it,a land of plenty.Nylon,meat,gasoline,and steel are rare.There are too many jobs and not enough workers.Money is very easy to earn but rather hard to spend,because there isn't very much to buy.Trains are always late and always crowded with"service men".The war will always be fought very far from America,and it will never end.Nothing in America stands still for very long,including the people who are always either leaving or on leave.People in America cry often.Sixteen is the key and crucial and natural age for a human being to be,and people of all other ages are ranged in an orderly manner ahead of and behind you as a harmonious 29 setting for the sixteen-year olds of the world.When you are 16,adults are slightly impressed and almost intimidated 30 by you.This is a puzzle finally solved by the realization 31 that they foresee your military future:fighting for them.You do not foresee it.To waste anything in America is immoral 32.String and tinfoil 33 are treasures. Newspapers are always crowded with strange maps and names of towns,and every few months the earth seems to lurch 34 from its path when you see something in the newspapers,such as the time Mussolini,who almost seemed one of the eternal leaders,is photographed hanging upside down on a meathook.

[02:07.35]21.Which statement best describes the main idea of the first paragraph?  A.Reality is what you make of it.  B.Time is like a river.  C.Emotions are powerful.  D.Every person has a special moment.

[02:06.35]22.Why does the author still clearly remember the war?  A.Franklin Delano Roosevelt was President.  B.It was his personal reality and part of life.  C.There was not much to buy.  D.The war would never end

[02:05.35]23.Why does the author think that adults are impressed with sixteen-year-olds?  A.Adults would like to be young.  B.Sixteen-year-olds do not waste things.  C.Sixteen-year-olds read newspapers  D.They will be fighting soon for adults.

[02:04.35]24.Which of the following can best describe the author's attitudes to the war?  A.It was very real for him yet he was not actively 35 involved.  B.It was real for him because he was a soldier at that time. C.It was very unreal to him.  D.The war was very disruptive to the people at home

[02:03.35]25.Why does the author say that string and tinfoil are treasures?  A.The war has made them scarce.  B.They are useful to 16-year-olds.  C.He liked them when he was 16.  D.People are very wasteful 36.

[02:02.35]Passage Four

[02:01.35]Questions 26 to 30 are based on the following passage.

[02:00.35]It is a curious paradox 37 that we think of the physical sciences as "hard,"the social sciences as"soft,"and the biological sciences as somewhere in between.This is interpreted to mean that our knowledge of physical system is more certain than our knowledge of biological systems,and these in turn are more certain than our knowlege of social systems.In terms of our capacity of sample the relevant universes,however,and the probability that our images of these universes are at least approximately correct,one suspects that a reverse order is more reasonable.We are able to sample earth's social systems with some degree of confidence that we have a reasonable sample of the total universe being investigated.Our knowledge of social systems,therefore,while it is in many ways extremely inaccurate 38,is not likely to be seriously overturned by new discoveries.Even the folk knowledge in social systems on which ordinary life is based in earning,spending,organizing,marrying,taking part in political activities,fighting and so on,is not very dissimilar from the more sophisticated images of the social system derived 39 from the social sciences,even though it is built upon the very imperfect samples of personal experience.In contrast,our image of the astonomical universe,or ever if earth's geological history,can easily be subject to revolutionary changes as new date come in and new theories are worked out.If we define the "security" of our image of various parts of the total system as the probability of their suffering significant changes,then we would reverse the order of hardness and as the most secure,the physical sciences as the least secure,and again the biological sciences as somewhere in between.Our image of the astronomical 40 universe is the least secure of all simply because we observe such a fantastically small sample of it and its record-keeping is trivial records of biological systems.Records of the astronomical universe,despite the fact that we learnt things as they were long ago,are limited in the extreme.Even in regard to such a close neighbour as the moon,which we have actually visited,theories about its origin and history are extremely different,contradictory 41,and hard to choose among.Our knowledge of physical evolution is incomplete and insecrue.

[01:59.35]26.The word "paradox"(Line 1,Para.1)means"_".  A.implication  B.contradiction  C.interpretation 42  D.confusion

[01:58.35]27.According to the author,we should reverse our classification of the physical sciences as "hard"and the social sciences as "soft"because_.  A.a reverse ordering will help promote the development of the physical sciences  B.our knowledge of physical systems is more reliable than that of social systems  C.our understanding of the social systems is approximately correct  D.we are better able to investigate social phenomena 43 than physical phenomena

[01:57.35]28.The author believes that our knowledge of social systmes is more secure that that of physical systems because_.  A.it is not based on personal experience  B.new discoveries are less likely to occur in social sciences  C.it is based on a fairly representative quantity of data  D.the records of social systems are more reliable

[01:56.35]29.The chances of the physical sciences being subject to great changes are the biggest because_.  A.contradictory theories keep emerging all the time  B.new information is constantly coming in  C.the direction of their development is difficult to predict  D.our knowledge of the physical world is inaccurate

[01:55.35]30.We know less about the astronomical universe than we do about any social system because_.  A.theories of its origin and history are varied 44  B.our knowledge of it is highly insecure  C.only a very small sample of it has been observed  D.few scientists are involved in the study of astronomy

[01:54.35]Vocabulary  (20 minutes)

[01:53.35]Directions:There are 30 incomplete sentences in this part.For each sentence there are four choices marked [A],[B],[C] and [D].Choose the ONE that best completes the sentence.Then mark the corresponding letter on the Answer Sheet with a single line through the centre.

[01:52.35]31.The technical glossary 45 include words which are never used outside the object or field_.  A.in view  B.in question  C.in case  D.in point

[01:51.35]32.Jim,the newly elected director,had to reorganize the entire office,he angrily complained of his_ ,who had been so incompetent 46 that everything was left in a mess.  A.successor  B.ancestor  C.predecessor 47  D.forefather 48

[01:50.35]33.Indian and Pakistan have_0.3 and 0.4 hectares of cropland person_.  A.relatively 49  B.proportionally  C.particularly  D.respectively

[01:49.35]34.Was a shelf of metal shaken to_the noise of thunder?  A.stimulate 50  B.simulate  C.duplicate  D.copy

[01:48.35]35.If James becomes governor,he is going to_the sales tax in our state.  A.abolish  B.abstain 51  C.abscond 52  D.absent

[01:47.35]36.The thief_the papers all over the room while he was searching the money.  A.abandoned  B.scattered 53  C.deserted 54  D.vanished

[01:46.35]37.The design of this architecture shows a great deal of_ .We have never seen a building of such a type before.  A.conventionality  B.originality 55  C.formulation  D.fascination 56

[01:45.35]38.The_person was committed to a mental hospital.  A.violent  B.thoughtless  C.insane  D.ignorant

[01:44.35]39.If you are told something_ ,you are expected not to pass on the information to anyone else.  A.secretively  B.specially 57  C.individually  D.confidentially 58

[01:43.35]40.Ben and a number of his friends were fishing for minnows at the edge of an_.  A.inlet  B.drainage  C.intersection 59  D.input 60

[01:42.35]41.At first I thought that you were totally right;_I was not sure.  A.on second thoughts  B.on second thought  C.on the second thought  D.on the second thoughts

[01:41.35]42.I don't know if the story is true,but I will_it.  A.conform  B.view  C.fortify 61  D.verify

[01:40.35]43.Your help is_for the success of the project.  A.indispensable  B.indicative  C.inevitable 62  D.inherent

[01:39.35]44.When I_myself,I found myself lying in bed,with Mother bending over me.  A.woke up  B.took on  C.picked up  D.came to

[01:38.35]45.Some of his suggestions have been adopted but others have been turned_as they are infeasible.  A.away  B.back  C.out  D.down

[01:37.35]46.He knows so much about the planets that I am sure it would be difficult to find his_.  A.similar  B.equal  C.likeness 63  D.sample

[01:36.35]47.At first the institute refused to buy the instrument,but this decision was_revised.  A.occasionally  B.consequently  C.successively  D.subsequently

[01:35.35]48.The chairman is a woman with great_and thus deserves our support.  A.intention  B.individualism  C.integrity  D.intensity 64

[01:34.35]49._to some parts of Tibet is still very difficult in winter,because they are still covered by thick snow.  A.Orientation 65  B.Access  C.Proceeding 66  D.Voyage

[01:33.35]50.Because of a_in the skirt,the girl was able to buy it at half price.  A.sign  B.fault  C.strip  D.flaw

[01:32.35]51.Some working experience is_for applicants 67 interested in this job.  A.available  B.permitable  C.acceptable  D.desirable

[01:31.35]52.Let us hope that_a nuclear war,the huma beings might survive.  A.in the event of  B.in relation  C.in the case of  D.with reference to

[01:30.35]53.Some researches confirmed that this kind of stomach was_in tropical countries.  A.perpetual  B.prospective 68  C.prevalent  D.presciptive

[01:29.35]54.I am afraid that you have to change your optimistic views_the tragic 69 news that has just arrived.  A.in terms of  B.in light of  C.in relation with  D.by means of

[01:28.35]55.There was once an_idea that the earth is the centre of the universe.  A.eternal  B.offensive  C.absurd  D.intrinsic

[01:27.35]56.By signing the contract we made a_to pay a rent of $50 a day.  A.concept  B.commission  C.confirm  D.commitment

[01:26.35]57.Mr.Thompson was deeply impressed by the Chinese'_and enjoyed the visit greatly.  A.humanity  B.hospitality  C.hostility 70  D.indignity 71

[01:25.35]58.When the board_to details,the proposed plan seemed impractical 72.  A.got down  B.set about  C.went away  D.came up with

[01:24.35]59.The system was redesigned to meet the network and finally_it in a profitable direction.  A.adapt  B.control  C.install  D.steer 73

[01:23.35]60.China and Japan shared many similarities in cultures,but they have used them differently according to different national_.  A.destiny  B.capability 74  C.engagement  D.temperament 75

[01:22.35]Cloze  (15 Minutes)

[01:21.35]Directions:There are 20 blanks in the following passage.For each blank there are four choices marked [A],[B],[C],and [D] on the right side of the paper.You should choose the ONE that best fits into the passage.Then mark the corresponding letter on the Answer Sheet with a single line through the centre.

[01:20.35]61.We are so accustomed to reading almost every week newspaper reports about new discoveries being made by man_  A.anyway  B.that  C.consequently  D.thus

[01:19.35]62.we tend to_the progress  A.make  B.achieve  C.take  D.obtain

[01:18.35]63.and_of scientific research for granted.  A.benefit  B.benefits  C.uses  D.advantages

[01:17.35]64.We_  A.assume  B.assure  C.resume  D.convince

[01:16.35]65.that science must continue to achieve its many_  A.misfortunes  B.miseries 76  C.missions  D.miracles

[01:15.35]66.Which become merely commonplace as_as they are replaced by greater ones.  A.possible  B.long  C.soon  D.well

[01:14.35]67._have made journeys through space,  A.Americans  B.People  C.Astronauts  D.We

[01:13.35]68.a_that once upon a time  A.phenomenon  B.invention  C.discovery  D.procession

[01:12.35]69.would have been_as unbelievable.  A.thought  B.considered  C.kept  D.remembered

[01:11.35]70._there are few people today  A.Even  B.Still  C.Yet  D.Already

[01:10.35]71.who feel anything_a mild interest in the discoveries that are being made by scientists.  A.like  B.except  C.but  D.else

[01:09.35]72.Industrialists 77 and engineers are busy taking_  A.care  B.charge  C.hold  D.advantage

[01:08.35]73.of the mineral deposits_ ,  A.desirable  B.available  C.acceptable  D.adjustable 78

[01:07.35]74.regardless of the fact that this_exploitation is deleterious.  A.beneficial  B.ruthless  C.scientific  D.good

[01:06.35]75.Nature is_their descendants altogether of these resources  A.protecting  B.accusing  C.depriving  D.isolating 79

[01:05.35]76._we so carelessly squander 80 on providing ourselves  A.which  B.what  C.so that  D.if

[01:04.35]77.with the_and not merely the necessities of life.  A.products  B.luxuries  C.conveniences  D.comforts

[01:03.35]78.We_to realize that we are responsible for the generations after ourselves,  A.try  B.manage  C.fail  D.come

[01:02.35]79.and even those who are_  A.proud  B.aware  C.fond  D.capable

[01:01.35]80.of this rarely take these responsibilities_enough.  A.seriously  B.gravely  C.solemnly  D.strictly 81

[01:00.35]Writing  (30 minutes)

[00:59.35]Directions:For this part,you are allowed 30 minutes to write a composition on the topic of Should Private Cares Be Encouraged in China.your part of writing should be no less than 120 words.

[00:58.35]Should Private Cars Be Encouraged in China

[00:57.35]1.A  2.B  3.A  4.C  5.B  6.A  7.B  8.A  9.C  10.C

[00:56.35]S1.mathematics  S2.branches  S3.classical  S4.Applied  S5.real  S6.pursue  S7.practical

[00:55.35]S8.Yet the very abstractness of mathematics makes it useful.

[00:54.35]S9.brush away the obscuring details and reveal simple patterns.

[00:53.35]S10.to calculate the positions of the planets at any time in the past of future and to predict the comings and goings of comets.

[00:52.35]11.B  12.C  13.A  14.D  15.A  16.D  17.C  18.C  19.B  20.D

[00:51.35]21.D  22.B  23.D  24.A  25.A  26.A  27.C  28.D  29.A  30.D

[00:50.35]31.B  32.C  33.D  34.C  35.A  36.B  37.B  38.A  39.D  40.A

[00:49.35]41.A  42.D  43.A  44.D  45.D  46.B  47.D  48.C  49.B  50.D

[00:48.35]51.D  52.A  53.C  54.B  55.C  56.D  57.B  58.A  59.D  60.D

[00:47.35]61.B  62.C  63.A  64.A  65.D  66.C  67.C  68.A  69.B  70.C

[00:46.35]71.C  72.D  73.B  74.B  75.C  76.A  77.B  78.C  79.B  80.A

[00:45.35]Writing  Should Private Cars Be Encouraged in China  A heated detate on private cars is underway in China.Car sellers energetically urge people to buy cars,whereas most Chinese,especially people in urban areas,oppose such an idea,saying that time is not right for each family to own a car.There are many reasons to encourage people to own cars.First,a car allows a person to travel long distances freely,safely and comfortably in all weathers.Second,if each family buys one car,millions of cars will be needed.As a result,auto industry,as well as its many related industries,will have a booming business,which will in turn accelerate the development of our economy.Furthermore,China can improve cars.Finally,the tax paid by car drivers will accelerate the construction of our highway network.There are,on the other hand,many reasons against it.Cars will use too much of our limited petroleum 82 resources,and cause many problems,such as air pollution,car accidents and traffic jams.So we will have to weigh every factor carefully before we make decisions about private cars.