A: May I go out to play football, Dad?B: No, you ________. You must finish your homework first. 

---Must I hand in my exercise book now, Mr. Zhao?---No, you ______. You may give it to me tomorrow.

— Do you know whose magazine is it?— I think it         be Lily’s, for we can find her name on the cover.

—The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job?—________ my students have a try?

—I wonder why Mr Green hasn't showed up at the meeting yet.—I'm not sure，but he________in a traffic jam driving here.