(一) 引入
1．I'm sorry to hear/learn that you are so crazy about...that...
2．In my opinion，it is wrong to...
3．I don't think it is a very good way to...
4．Thank you for your letter asking me about...
5．I'm writing to persuade you to quit/give up...
(二) 阐述
1．Here are my reasons.First of all，I think it would be better if...
2．The reasons for...are as follows.First，...Second，...Last but not least，...
3．On the one hand，...; on the other hand，...
4．The reason for...is that...
5．No one can ignore the fact that...
6．If I were you，I would...
