​III. Choose the correct answer: 1. “Have you seen John?” “No. But he _________ be studying in the library.
A. will B. should C. needn’t D. may
2. As I won’t be at home tonight, I ____ my homework during my lunch break.
A. neeed to do B. have to do C. can do D. might do
3. Passengers ___ smoke until the signs have been switched off.
A. mustn’t B. can’t C. needn’t D. mightn’t
4. There are a lot of tickets left, so you ___ pay for the tickets in advance.
A. mustn’t B. won’t C. shouldn’t D. don’t have to
5. You ___ put anything on the shelves until the glue has set hard.
A, couldn’t B. muctn’t C. don’t have to D. needn’t
6. I ___ my best suit to the party yesterday; everyone else was very casually dressed.
A. needn’t wear B. mustn’t wear C. needn’t have worn D. mustn’t have worn
7. I didn’t meet him yesterday. He ___ on business.
A. must go B. should go C. must have gone D. should have gone
8. “What are you doing this weekend?” “I haven’t decided yet. I ____ go on a picnic with my family.”
A. may B. may not C. must D. needn’t
9. You ___ wash the car. I just had it done yesterday.
A. mustn’t B. needn’t C. must D. may not
10. It’s a secret. You ___ let anyone know about it.