选择句子，补全对话。

A. Let's clean the classroom. B. Good morning! C. Let me help you. D. It's so big. E. Let me clean the windows.

Chen Jie: Good morning!

John:

Chen Jie: This is our new classroom.

John:

Chen Jie: But(但是) it's dirty(脏的).

John:

Chen Jie: OK!

John: Let me clean the desks and chairs.

Chen Jie:

Zhang Peng: Hi，friends.

John and Chen Jie: Thank you!