题目内容：

根据对话情景和内容，从对话后所给的选项中选出能填入每一空白处的最佳选项，并在答题卡上将该选项涂黑。选项中有两个为多余选项
Acceptionist：Can I help you?
Daniel：     Yes, I’m doing some research on Roman civilization. __1.___
Acceptionist：These books over here are about ancient history. ___2.__
Daniel：     Can I check this one out?
Acceptionist：___3.__. It’s for reference only, so it must stay in the library. But you’re welcome to look through it.
Daniel：     Ok. ___4.__
Acceptionist：All right. They’re due back next Wednesday.
Daniel：     ___5.__

A．I’m sorry.

B．It doesn’t matter.

C．Thanks for your help.

D．They might be helpful.

E. They must be useful for you.
F. And I’d like to check these books out.
G. Do you have any books on the subject?