从方框中找出下列各句的最佳应答语，并将序号A-E填在题前括号内。

A. OK.    B. Thank you.    C. Two books. D. It's on the fan.           E. Yes, it is.

（）1. Let me help you.

（）2. Where is the bee?

（）3. What's on the desk?

（）4. Is it your picture?

（）5. Let's clean the classroom.