—Shall we have a smoke here?
—No, we _____ because this is gas station and the worker is carrying some petrol.
| A．can’t | B．needn’t |
| C．mustn’t | D．won’t |
In crowded places like airports and railway stations, you __________ take care of your luggage.
| A．can | B．may |
| C．must | D．will |
The teacher __________ have thought Johnson was worth it or she wouldn’t have wasted time on him, I suppose.
| A．should | B．can |
| C．would | D．must |
The weather turned out to be fine yesterday. I __________ the trouble to carry my umbrella with me.
| A．should have taken | B．could have taken |
| C．needn’t have taken | D．mustn’t have taken |
You know he is not going to let us leave early if we __________ get the work done.
| A．can’t | B．may not |
| C．shouldn’t | D．mustn’t |
There’s no light on — they __________ be at home.
| A．can’t | B．mustn’t |
| C．needn’t | D．shouldn’t |