23. Why ______________? For one thing, ______________. For another, ______________. Perhaps the main reason is ______________.

22. There are, I think, two main reasons for ______________. In the first place, ______________. In the second place, ______________. Therefore, ______________.

21. Well, why is there ______________? I think there might be two reasons. One is ______________, and the other is ______________.

20. There are probably many reasons for ______________. First, ______________. Second, ______________. Finally, ______________.

19. However, if not managed properly, ______________ can create many problems. Sometimes ______________. Furthermore, ______________. Therefore, ______________ has been gaining public concern.

18. ______________ is necessary and important to our country’s development and construction. First, ______________. What’s more, ______________. Most important of all, ______________.

17. There are some other people, who ______________. Their reasons are different, something for ______________, sometimes for ______________, and sometimes simply for ______________.

16. It is high time that something was done about it. For example, ______________. In addition, ______________. All these measures will certainly ______________.

15. There are several measures for us to adopt. First, we can ______________, there are a number of advantages of ______________. Another solution is to ______________.

14. On the contrary, there are some people in favor of ______________. They believe ______________. Moreover, they think ______________.