【正文】 I teach because I like the freedom to make my own mistakes.　　12) I have left out the most important reasons why I teach.　　13) The reason for this is that technology feeds on itself　　14) Owing to fierce petition among the airlines, travel expenses have been lowered considerably.　　15) Owing to the lack of coordination between the two sides, the project has made little progress so far.　　16) The teacher tried to encourage her students to bee less dependent on their parents because they would sooner or later have to take care of themselves.　　17) Yet the public has every reason to be wary of professional deception(欺騙)　　18) At times, they see important reasons to lie for the patient’s own sake.　　　　1)One of the greatest problems facing the 21st century will be what to do with all the rubbish produced in the world.　　2) The frequent use of drugs (毒品) is a serious problem among some American young people.　　3) To travel abroad is a desire shared by many people, but few can afford to do it.　　4) Man still has a lot to learn about the most powerful and plex part of his bodythe brain.　　5) We had a ling debate as to whether we should spend so much money on space technology.　　6) Many people have the bad habit of spending money on impulse.　　7) The custom of having one’s marriage arranged by parents has disappeared in many parts of the world but continues in some Asian and African countries.　　8) Cheating is now considered to be a major problem in colleges and universities.　　9) No agreement was reached as to how the plan should be carried out.　　10) True, the cost of living has gone up, but so have the workers ‘wages.　　11) I had trouble learning or doing something important to me.　　12) She had a little trouble with her typing.　　13) Many university students experience severe tension (緊張) as final exams draw near.　　14) Until recently this hostile (敵對(duì)的) attitude towards daydreaming was the most mon one .　　15) Many people find it harder and harder to keep up with the radical changes that characterize our time.　　16) If this project is to be carried out, we must have all the help that modern technology can supply.　　17) When the days seem to go by slowly, you can tell that you’re not enjoying yourself.　　18) Large amounts of food imports placed a great strain(負(fù)擔(dān)) on the country’s gold reserve(黃金儲(chǔ)備)　　19)Corruption(腐敗) in government is not tolerated in any country that wants to achieves rapid economic growth and improve the life of its citizens.　　20) At first thought, the problem seems far too involved (復(fù)雜) , but it can certainly be solved when seriously dealt with .　　21) Colleges are not always adjusted to the needs of society to they need reform from time to time.　　22) We’re all used to thinking that work provides the material things of life.　　18. 表示可能性　　1)If I wasn’t able to avoid a mistake, chances were that no other surgeon could have, either.　　2) I think it is very unlikely that he will get the job。 it is the focus of their lives, the source of their identity and creativity.　　5) Rather than a punishment or a burden, work is the opportunity to realize one’s potential.　　6) Few pastimes bring a family closer together than gathering around and listening to mother or father read good story　　7) Man differs most from all the other animals in his ability to learn and use language but we still do not know exactly how this is done.　　8) Generally speaking(In general), young people are less conservative(保守)than old people.　　9) The way the brain works is far more plicated than they had thought.　　10) The more scientists find out, the more questions they are unable to answer.　　11) Many Americans choose to travel by car rather than by any other means of transportation.　　12) Worse perhaps was the idea of Saturday afternoon cricket.　　13) There is no surgical patient I cannot treat petently, treat just as well as or better that any other surgeon.　　14) Social customs are different from what they used to be fifty years ago.　　15) He has to feel that he’s good as and probably better than any other surgeon in the world.　　16) Behavior which may be considered quite strange in one culture is often looked upon as pletely normal in another.　　17) It is as hard to pass her by without giving her some money as it is to ignore the collection box in church.　　18) It is as morally hard to turn her away as it is a lost dog.　　19) Attitudes towards daydreaming are changing in much the same way that attitudes towards night dreaming have changed.　　20) We accept the authority of our parents when we are young, but as we mature we may begin to question their advice.　　1) Without the distraction of TV, they might sit around together after dinner.　　2) As long as the brain is given plenty of exercise it keeps its power.　　3) Were it left to me to decide whether we should have a government. without newspapers of newspapers without a government, I should not hesitate a moment to prefer the latter. 　　4) Without a degree and with no experience in teaching my chances of getting the job were slim.　　5) With the introduction of a new assembly line, we hope to step up the production of our factory.　　6) Whether day or night. Summer or winter, temperatures in the underground world would remain equable and nearly constant.　　7) However odd and repulsive(古怪難受)underground living may seem at first thought, there are things to be said for it.　　　　1) Everything from the generation gap to the high divorce rate to some forms of mental illness.　　2) Take, for example, the emergency situations that we encountered almost every night.　　3)