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

2. The answer to this problem involves many factors.

3. The phenomenon mainly stems from the fact that...

4. The factors that contribute to this situation include...

5. The change in rgely results from the fact that...

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

7. Part of the explanations for it is that ...

8. One of the most common factors (causes ) is that ...

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

10. Perhaps the primary factor is that …

11. But the fundamental cause is that ...

3)结果

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...

4)批驳

1)It is true that ..., but one vital point is being left out.

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

3) Some people say ..., but it does not hold water.

4) Many of us have been under the illusion that...

5) A close examination would reveal how ridiculous the statement is.

6) It makes no sense to argue for ...