-Is your father a teacher of English in the No.l Middle School?
-No! But he _________ English there for ten years.
| A．has taught | B．has been teaching |
| C．taught | D．had taught |
Believe it or not, crying is a way you can imagine ______ pressure.
| A．relieving | B．to relieve |
| C．relieved | D．relieve |
__________ the students who have taken part in the sports game is unknown.
| A．A great number of | B．A great deal of |
| C．A large number of | D．The number of |
_______, the more exercise you do, the richer your knowledge will be.
| A．It is known to all | B．Which is known to all |
| C．As we all know | D．As is known to all that |
His mother happened _______ when his program was shown on Channel Young.
| A．watching TV | B．to watch TV |
| C．to be watching TV | D．being watching TV |
By the time he was ten, Edison _________ experiments in chemistry.
| A．had already done | B．already had done |
| C．was already doing | D．already did |