根据对话内容，从方框内的选项中选出能填入空白处的最佳选项，其中有两个为多余选项。

A: It's very late. Are you still on the computer?

B: Well, yes.

A: What kind of e-mails?

B: Some are messages from my teacher and some are from my friends.

A: Do you have to write them back right away?

B:Usually people want a quick reply.

A:

B: I've already had 50 people's address in my address book! And

A:E-mail is really very convenient(方便的).
 

A. I think e-mail is one of the best ways to communicate with others. B. I've got so many e-mails to go through. C. I agree with you. D. Of course! E. How many e-mails addresses have you had? F. I feel like playing computer games. G. I am not sure whether I'm right or wrong.