We _____ on this project for four hours. Let’s have a rest.
| A．are working | B．have been working |
| C．worked | D．had worked |
I posted the letter some time _____ the week .
| A．in | B．during | C．throughout | D．within |
If you ______ stop smoking , you can only expect to have a bad cough .
| A．won't | B．would not | C．do not | D．can not |
There must be ______ book which could help .
| A．some | B．any | C．one | D．one useful |
The young man spent as much time as he ______ over his lessons.
| A．went | B．can go | C．could going | D．could to go |
--- Who should I send this message to ?
--- The mayor is the one ____ ?
| A．to send it | B．to be sent | C．for sending | D．to send it to |