选句子补全对话。其中有两项多余。

A. They are singing. B. Yes, he is. C. Yes, we are. D. What are you doing? E. She is flying a kite. F. We are dancing. G. No, she isn't.

Zhang Peng: Look, mum. This is the photo of my summer camp(夏令营).
Mum: Oh! It's very exciting. What is Chen Jie doing?
Zhang Peng:
Mum: Is John playing chess(下棋)?
Zhang Peng:
Mum:
Zhang Peng: I'm reading a storybook.
Mum: What are the girls doing?
Zhang Peng:
Mum: Are you having a good time?
Zhang Peng:
Mum: How wonderful!