1.There be结构
1） There are other techniques that might help you with you studying.
2） There is more entertainment in a good book than is a month of typical TV programming.
3） Most curious of all，there was no quality control whatsoever.
4） There were no breaks in the day to relieve the boring work.
5） In the past 50 years there has been a great increase in the amount of research being done on the brain.
6） There are so many of thee paths and so many metal particles that it is impossible to land a flying saucer without is being smashed by one.
7） There is much that we can learn from him today.
8） There are two sides to every question. If you take one side with decision and act on it with effect，those who take the other side will of course resent your actions.
9） There is no sense（道理）in leaving important decisions to inexperienced people.
10） There is little sense in treating the child so severely. After all he is too young to know that he was doing wrong.
11） There is no surgical patient I cannot treat competently，treat just as well as or better than any other surgeon.
12） There were still situations in which I couldn't be certain my decision had been the right one.
13） There's no right or wrong in the situation. There's just luck.
14） There's no way to prepare for the next time—no intelligent response to a gun.
15） There is no way to stop the process of aging. In fact，we can only delay it.
16） There are other indications that high school cheating may be on the rise （还有一些迹象表明……）.
17） There is some evidence that dishonesty may ebb and flow（起伏波动）.
18） Today there is evidence that the time between each of the steps in this cycle has been shortened.
19） There can be on doubt that he is the right person for the job.
20） There is no doubt that their support will make a difference in out cause .
21） There is no doubt that these measures will contribute to the solution of the problem.
22） There is no doubt that Jim had more talent than anybody who ever played football.
23） There's no substitute（替代物）for practical experience.
24） There is urgent need to debate this issue openly.
25） There are tow ways in which one can own a book.
26） There have been some small fluctuation（波动）in the past year，but by and large prices have remained stable.
2.It 结构
1） It is advisable to exercise（拥有）patience in dealing with such complicated situations.
2） It is advisable to place important telephone numbers nest to the phone in case of an emergency.
3） It is biologically reasonable for deer to reduce their cost of living to increase their chances of surviving in winter.
4） It is essential that the increase in production should be geared to （适应）the increase in public demand.
5） It is necessary that young and old people should communicate more with each other.
6） It is thoughtless of some parents to allow their children to watch whatever program is on television.
7） It is incredible(不可思议)that he ate the big cake just in tow bites.
8） It was obvious to everyone that the marriage would sooner or later end in separation if not diverce.
9） It was clear that Dad could do no more than he was doing already.
10） It is certain that fresh air and exercises are more valuable than medicine.
11） It is certain that with determination and hard work you will succeed eventually.
12） It was quite apparent that both sides were making a great effort to win the prize.
13） It was almost impossible for an Indian to gain even a fair education an extremely difficult，as a result，for an Indian to rese high in life.
14） It is easy to fall into bad habits but very difficult to break away form them.
15） It's not easy to size up （估计）the situation right now. For we are not well informed on recent developments.
16） It is not easy to say exactly what each part of the brain does.
17） It is not wise to change you money into U.S. currency.
18） It was not until about 1600B.C. when the chariot （马拉战车）was invented that the maximum speed was raised to roughly twenty miles per hour.
19） It is only recently that science has begun to give us some idea of how the brain really works.
20） It was not until the century that man realized that the whole of the brain was involved in the working of the mind.
21） It is conflict and not unquestioning agreement that keeps freedom alive.
22） It was in times of crisis that I finally found out what he was really like.
23） It took the human race millions of years to attain that record.
24） It took a mere twenty-year flick（一瞬）of time to double the limit again.
25） It takes （took）sb. some time to do sth.
26） If it takes less time to bring a new idea to the marketplace，it also takes less time for it to sweep through the society.
27） It will take the council a few weeks to judge the situation before it takes any further action.
28） It is well known that many of our problems are caused at least in part by failure to communicate.
29） It is fairly well known that wild animals survive form year to year by eating as much as they can during times of plenty.
30） It is probably less well known that even with their stored fat, wild animals spend less energy to live in winter than in summer.
31） It remains unknown whether there are intelligent beings outside the solar system.
32） It has been pointed out that in 6000 B.C. the fastest transportation available to man over.
33） It is now thought that the more work we give our brains，the more work they are able to do.
34） It can be argued that such a response may not mean much （有人认为……）.
35） It is reported that the electronic industry is going on rapidly in recent year.
36） It is reported that there has been a decrease in the annual birth rate over the last two decades.
37） It is estimated that the total expenses in the trial manufacture of the new products will come to 30,000 yuan.
38） Once it was thought that nighttime dreams interfered with our needed rest.
39） It has been observed that unemployment brings enormous psychological troubles.
40） Even so，it seemed to him that he was part of the whole event.
41） It seems to me that the Americans are a highly mobile people. Most of them like to travel whenever they get the chance.
42） It seemed to me that the only thing that mattered was to get her husband back to her.
43） But it is only because it is my work to do so.
44） It is an encouraging sign that people's purchasing power（购买力）is on the rise.
45） It is common knowledge that chalk absorbs moisture（湿气）from the air.
46） It might be a way to avoid the indignity of having to ask for money all the time.
47） It used to be a popular belief the we could foretell a person's future on the basis of the date and time of his birth.
48） It pays in the long run （从长远的角度看……）to introduce new technique.
49） It is time for out symbols of technology to change-to catch up with the quickening changes in technology itself.
50） It has been only twenty-five years since television came to one of people's pastimes.
51） It may well come as a surprise to learn that not only psychologists but other behavioral scientists have come to accept the positive contribution of work to the individual's happiness and sense of personal achievement.
3.动名词或分词结构
1） Improving your study habits will improve your grades.
2） Teaching gives me pace，and variety，and challenge，and the opportunity to keep on learning.
3） Being very short of money and wanting to do something useful, I applied.
4） Having little in common is a frequent cause of divorce.
5） Owing sets of books is useless unless you read them.
6） Drinking，eating，and smoking excessively can do severe harm to even a young person's health.
7） The art of communication requires learning the language and culture of the audience.
4.递进式结构
1） Fresh vegetables are nutritious（有营养的）；furthermore，they re cheaper than frozen ones.
2） We will not only bring joy into other people's lives，but also added happiness into our own.
3） But teaching offers something beside money and power；it offers love. Not only the love of learning and go books and ideas，but also the love that a teacher feels for his students.
4） Not only should you limber up （做准备活动） before exercising，but you must also be sure to cool down afterwards.
5） They do not seem to like one anther very much. Neither are they too keen on conventional people （正统的人）.