I am fond of my sister but she has one serious shortcoming. She _________ be really stubborn.

 -Must I send my uncle an e-mail now, Dad? -No, you ____.You____ do that after you finish your homework.

--- I spent two weeks in London last summer. --- Then you must have visited the British Museum during your stay, _______ you?

For the safety, everyone _________ obey the traffic rules when he is driving or walking.

－Must I finish my composition (作文) right now?－No, you _______.You can hand it in tomorrow.