1. 选择合适的句子补全对话。

A. Is it big? B. It's a book about Beijing. C. Beijing is a big city. D. It's my house. E. Yes, it is.

A: What's this?

B:

A:

B: Yes. It is very big!

A: Whose house is it?

B:

A:

B: No, it isn't. But it's very beautiful.

A.