He made another wonderful discovery, ______ of great importance to science.
| A．which I think is | B．which I think it is |
| C．which I think | D．I think which is |
It was____to watch small childen play games.
| A．pleased | B．pleasure | C．glad | D．fun |
I remember___for the job,but I forget the exact amount.
| A．to be paid | B．being paid | C．to paid | D．paying |
The reason ____he gave for not coming was ____his mother wouldn’t allow him to.
| A．for which,that | B．which,because | C．why,that | D．which,that |
---We haven’t heard from Jane for a long time.
----What do you think_____to her?
| A．was happening | B．to happen | C．has happened | D．having happened |
—I knocked but nobody answered the door.
----They _____asleep then and didn’t hear you.
| A．must be | B．should be | C．must have been | D．should have been |