The computer was used in teaching. As a result, not only __________，but students became more interested in the lessons.
| A．saved was teachers' energy |
| B．was teachers' energy saved |
| C．teachers' energy was saved |
| D．was saved teachers' energy |
— I’ve taken someone else’s green sweater by mistake.
— It ______ Harry’s. He always wears green.
| A．has to be | B．will be | C．mustn’t be | D．could be |
I was on the highway when this car went past fol. Lowed by a police car. They ______ at least 150 kilometers an hour.
| A．should have been doing | B．must have been doing |
| C．could have done | D．would have done |
There _____ be any difficulty about passing the road test since you have practiced a lot in the driving school.
| A．mustn’t | B．shan’t | C．shouldn’t | D．needn’t |
I ______ have been more than six years old when the accident happened.
| A．shouldn’t | B．couldn’t | C．mustn’t | D．needn’t |
John, look at the time. ______ you play the piano at such a late hour ?
| A．Must | B．Can | C．May | D．Need |