________ is known to all is that effective measures should be taken to deal with the problem of the overexploitation of our resources.
| A．What | B．It |
| C．As | D．Which |
The staff(员工) of the school ______to the expert’s lecture．for they feel interested in it．
| A．are listening | B．is listening | C．1istens | D．has listened |
The professor managed to find some grounds (facts)_________his arguments．
| A．to be based on | B．to base on |
| C．which to base on | D．on which are based |
I would like a job which pays more，but _______I enjoy the work I’m doing at the moment．
| A．in other words | B．on the other hand | C．for one thing | D．as a matter of fact |
----- Have you ______ some new ideas?
------ Yeah．I’ll tell you later.
| A．come about | B．come into | C．come up with | D．come out with |
Leave your key with a neighbor ______you lock yourself out one day．
| A．ever since | B．even if | C．soon after | D．in case |