Choose the correct option to fill in the gaps...
11. The children ............ have finished their homework by the time we get home, but I’m not sure.
a) aren’t able to b) have to c) might
12. Most children ............ wear school uniforms in private schools.
a) might b) must c) can
13. Why didn’t you phone Paul? He ............ have given a lift to the airport yesterday.
a) can b) ought to c) could
14. A. “Isn’t that John over there?” B. “It ......... be John, he’s at work now.”
a) mustn’t b) can’t c) shouldn’t
15. The new student ......... be German, he doesn’t speak German fluently.
a) shouldn’t b) mustn’t c) can’t
16. Someone’s knocking at the door. It ............... be James; he said he’ come round today.
a) ought to b) must c) can’t
17. You ............... buy a dictionary; there are a lot in class.
a) may not b) mustn’t c) needn’t
18. People ............ fasten seat belts when travelling by car.
a) must b) can c) should
19. Dad is taking a nap; you ............ make so much noise, children.
a) mustn’t b) might not c) needn’t
20. We’ve run out of coffee. We ............ get some tomorrow.
a) may b) must c) might
