1. 从方框里选择句子把对话补充完整 (只填序号)。

A. Let me help you. B. Let's clean the classroom. C. Let me clean the windows. D. Really?

A: We have a new classroom?

B: Let's go and see.

C: It's so big! But it's dirty(脏的).

A:

ABC: OK.

A: Let me clean the teacher's desk.

C:

B:

C: thank you.