Immediate action must be________before it is too late.
| A．done |
| B．taken |
| C．used |
| D．accepted |
It is thein this country to go out and pick flowers on the first day of the spring．
| A．use | B．custom | C．habit | D．normal |
Michael be a policeman, for he is much too short．
| A．needn’t | B．can’t | C．should | D．may |
The teacher apologized late．
| A．to his students to arrive | B．to his students for arriving |
| C．at his students to arrive | D．at his students for arriving |
Smoking is a bad habit．You should it．
| A．throw | B．get away with | C．get rid of | D．throw away |
He left the key ______ he had been an hour before.
| A．what | B．that | C．where | D．which |