1. As we’re students, we _______ obey the school rules.
A. can B. may C. must D. could
2. —Would you come to my birthday party tomorrow evening?
—I’m afraid I _______. I have to look after my sister.
A. wouldn’t B. can’t
C. won’t D. mustn’t
3. —Have you decided where to go for your summer vacation?
—Not yet. We _______ go to Qingdao. It is a good place for vacation.
A. may B. should C. need D. must
