根据情景选择正确的句子。

1. 当你夸奖别人是一个有用的女孩时，说：[ ]

A. I'm a helpful girl.

B. You're a helpful girl.

C. You're a beautiful girl.

2. 当你问别人会做什么时，说：[ ]

A. What can you do?

B. What do you do?

C. Where are you?

3. 当你要别人倒垃圾，并且要小心时，说：[ ]

A. You can empty the trash, and be careful.

B. Please sweep the floor, and be careful.

C. Please empty the trash, and be careful.

4. 当你告诉别人你不会做某事并很抱歉时，说：[ ]

A. Excuse me, I can't do it.

B. I'm very sorry. I can't do it.

C. I'm sorry. I don't know.