从方框中选出恰当的句子补全对话。

A. On the school bus. B. Thank you. C. My new hat is in it. D. I lost my bag. E. It's yellow.

A: You are sad, Sue. What's the matter with you?

B:

A: Where did you lose it?

B: .

A: What color is it?

B:

A: What's in it?

B:

A: Don't worry. I found a bag on the school bus.

B: That's my bag!