In order to keep healthy, you’d better _______.
| A．not to smoke | B．not smoke |
| C．don’t smoke | D．smoking |
I don’t know _______.
| A．where can we buy the tickets |
| B．how much it costs to fly to Shanghai |
| C．who is he waiting for |
| D．why was he late for school this morning |
— Is the man over there Mr Black?
— It _______ him. He has gone to England.
| A．must be | B．can’t be |
| C．may be | D．mustn’t be |
They _______to that supermarket many times since they moved here.
| A．have been | B．have gone |
| C．will go | D．went |
Tom likes cars. He enjoys _______ model cars of all kinds.
| A．collects | B．collected |
| C．to collect | D．collecting |