从方框中选出下列各句的最佳应答语。

A. No, they aren't.    B. No, he isn't. C. He is kind and helpful. D. Mr Wang. E. Yes, I do.

（）1. Who is your science teacher?

（）2. Are Sam and Tom hard-working?

（）3. Do you know Mrs Black?

（）4. What's Bob like?

（）5. Is he polite?