单选题 《复合题被拆开情况》A: It’s very late. Are you still on the computer?B: Well, yes.【D5】________A: What kind of e-mails?B: Some are messages from my friends and some are from the relatives.A: Do you have to write them back right away?B: Of course! Usually people want a quick reply.A: How many e-mails addresses have you had?B: I’ve already had 50 people’s address in my address book!【D6】________A:【D7】________E-mail is really very convenient.A. And 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. I feel like playing computer games. 《问题》：【D6】