一)原因

　　1.A number of factors might contribute to (lead to )(account for ) the phenomenon(problem).

　　2. The change in ...largely results from the fact that...

　　3. We may blame ...，but the real causes are...

　　4.Another contributing factor (cause ) is ...

　　二)比较

　　1.The advantages of A are much greater than those of B.

　　2.For all the disadvantages， it has its compensating advantages.

　　3.A and B has several points in common.

　　4. People used to think ...， but things are different now.

　　三)批驳

　　1.There is a grain of truth in these statements， but they ignore a more important fact.

　　2.Some people say ...， but it does not hold water.

　　3.It makes no sense to argue for ...

　　4.Too much stress placed on ... may lead to ...

　　四)后果

　　1. It may give rise to a host of problems.

　　2. The immediate result it produces is ...

　　3. It will exercise a profound influence upon...

　　4. Its consequence can be so great that...

　　五)举例

　　1.A good case in point is ...

　　2.Such examples might be given easily.

　　六)证明

　　1.No one can deny the fact that ...

　　2.Recent studies indicate that ...

　　3.There is sufficient evidence to show that ...

　　七)开篇

　　1.Many nations have been faced with the problem of ...

　　2.Never in our history has the idea that ... been so popular.

　　3.Faced with ...， quite a few people argue that ...

　　4.According to a recent survey， ...

　　5.With the rapid development of ......

　　八)结尾

　　1. From what has been discussed above， we can draw the conclusion that ...

　　2. It is high time that strict measures were taken to stop ...

　　3. With the efforts of all parts concerned， the problem will be solved thoroughly.

　　九)解释原因的

　　1.to begin with， then， furthermore， finally(强烈推荐)

　　2.to start with， next， in addition， finally(强烈推荐)

　　3.first and foremost， besides， last but not least(强烈推荐)

　　4.most important of all， moreover， finally

　　5.on the one hand， on the other hand(适用于两点的情况)

　　6.for one thing， for another thing(适用于两点的情况)

　　十)前后连接词

　　then， therefore， consequently， accordingly， hence， as a result， for this reason， so that