Our teacher is always busy preparing lessons until 11 o’clock at night, _____we students have gone to sleep.
| A．that time | B．by which time | C．by that time | D．which time |
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 |