_____ these experiments were successfully completed would we think of
going into humans.
| A．If only | B．So that | C．Only if | D．Even if |
My parents have promised to come to see me before I _______ for Africa.
| A．have left | B．leave | C．left | D．will leave |
It just isn’t fair_____ I was working as a waiter last month; my friends were lying on the beach. .
A whenever B. though C. for D. while
The traffic is heavy this day, I _____ arrive a bit late, so could you save me a place?
| A．can | B．must | C．need. | D．might |
____ is the power of TV that it can make a person suddenly famous.
A. Such B This C That D So
____ , you need to give all you have and try your best. 
| A．Being a winner | B．To buy a winner |
| C．Be a winner | D．Having been a winner |