About two hundred people are working in his company now，most of________ were once out of work.
| A．which | B．who | C．that | D．whom |
You should let your children play ______ you can see them.
| A．where | B．when |
| C．in which | D．that |
Now he works in the factory ______ his father used to work.
| A．where | B．when |
| C．in which | D．that |
The visitor asked to have his picture taken _______ stood the famous tower.
| A．that | B．at which |
| C．when | D．where |
They kept trying _____ they must have known it was hopeless.
| A．if | B．because |
| C．when | D．where |
Why do you want a new job ______ you’ve got such a good one already?
| A．that | B．where |
| C．which | D．when |