__________ is certain is __________ prevention is more important than treatment.
| A．It; that |
| B．What; that |
| C．As; what |
| D．What; what |
With ______ help of his teachers, he made ______ great progress in his study.
| A．a; a | B．the; 不填 |
| C．the; the | D．a; 不填 |
I _____ in the street when someone _____ me.
| A．walk; called | B．walking; calling |
| C．was walking; called | D．walked; called |
The number of people who _______ invited to the meeting _____ fifty, but a number of them _____ absent for different reasons.
| A．were; was, was | B．was; was, were |
| C．were, was; were | D．were; were, was |
The early pioneers had to _____ many difficulties to settle down on the new land.
| A．get along with | B．go after |
| C．go over | D．go through |
The teacher called Tim’s mother ________ what he had done in the test.
| A．because of | B．because |
| C．since | D．as |