33．—Where’s that report?
—I brought it to you ______ you were in Mr. Black’s office yesterday.
| A．if | B．when | C．because | D．before |
32. The cost of living in Glasgow is among the lowest in Britain, ______ the quality of life is probably one of the highest.
| A．since | B．when | C．as | D．while |
31. ______ I really don’t like art, I find his work impressive.
| A．As | B．Since | C．If | D．While |
30. He was told that it would be at least three more months ______ he could recover and return to work.
| A．when | B．before | C．since | D．that |
29. The field research will take Joan and Paul about five months; it will be a long time ______ we meet them again.
| A．after | B．before | C．since | D．when |