We must be aware of the potential causes of traffic accidents and act to prevent them—this is true ____ everyone.
| A．for | B．to | C．with | D．of |
I ______ have been more than six years old when the accident happened.
| A．shouldn’t | B．couldn’t | C．mustn’t | D．needn’t |
He _____ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside.
| A．should | B．must | C．wouldn’t | D．can’t |
John, look at the time. ______ you play the piano at such a late hour ?
| A．Must | B．Can | C．May | D．Need |
Tom, you _____ leave all you clothes on the floor like this !
| A．wouldn’t | B．mustn’t | C．needn’t | D．may not |
A left –luggage office is a place where bags _____ be left for a short time, especially at a railway station.
| A．should | B．can | C．must | D．will |