It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
| A．process | B．attention | C．measure | D．part |
It was a nice meal，__________ a little expensive.
| A．though |
| B．whether |
| C．as |
| D．since |
__________ all of them are strong candidates, only one will be chosen for the post.
| A．Since |
| B．While |
| C．If |
| D．As |
You will be successful in the interview __________ you have confidence.
| A．before |
| B．once |
| C．until |
| D．though |
These examples show that all individuals，__________ they are rich or poor, should be responsible __________ they are involved in law.
| A．if; when |
| B．if; as long as |
| C．whether; as long as |
| D．whether; since |
__________ you may have, you should gather your courage to face the challenge.
| A．However a serious problem |
| B．What a serious problem |
| C．However serious a problem |
| D．What serious a problem |