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.
