给句子选择正确的答语。

A．We mustn't play with matches.

B．Yes, I do.

C．No, you can't.

D．No, you mustn't. The smoking room is over there. You can smoke there.

E．We must wash hands.
【小题1】What must we do before lunch? （______）
【小题2】What mustn't we do at home? （______）
【小题3】Do you know about fire safety? （______）
【小题4】May I smoke here? （______）
【小题5】Can I throw the stone into the river? （______）