If human beings had been a bit less greedy and cruel, more birds and animals dying out.
| A．ought to avoid | B．could have been avoided |
| C．should have avoided | D．might have avoided |
The school headmaster forbids ______ in the office.
A. smoking B. to smoke C. us smoke D. from smoking
We were listening closely to the lecture yesterday evening when suddenly the light ________.
| A．had been gone out | B．go out |
| C．was gone out | D．went out |
________ the manager has arrived, we can begin our discussion right away.
| A．If | B．When | C．Now that | D．Even if |
He has always insisted on _______ Dr Turner instead of Mr Turner.
| A．been called | B．called | C．calling | D．being called |
After a short ________, I got my bag from the thief’s hand successfully.
| A．exchange | B．explanation | C．encouragement | D．struggle |