—I didn’t see her yesterday,I looked for her everywhere,but couldn’t find her.

—Oh,but you　　 .She was working in the office.

A.must have　　　B.ought to　　　　C.ought to have　　　D.can’t have

We believe she can win the game, ______?

　 A. don’t we 　 B. do we  C. can we 　 D. can’t we

― Why does Sara know so much about Angkor Wat?

― She ________have been there, or...

A. must　        B. oughtn't to       C. may　           D. Can't

We believe she can win the game, ______?

　 A. don’t we 　 B. do we  C. can we 　 D. can’t she

—What do you think we can do for our aged parents?

—You __ ___ do anything except to be with them and be yourself.

A. don’t have to　　　 　 B. oughtn’t to　 C. mustn’t　　　　 D. can’t