________ it is, the boy never seems to be able to finish it off.
| A．However interesting a book |
| B．Whatever interesting a book |
| C．How interesting a book |
| D．What an interesting book |
The new system needs to be in operation for five months ________ it can be updated.
| A．as | B．while |
| C．before | D．once |
We can't wait any longer ________ we'll miss the plane.
| A．or | B．but |
| C．so | D．yet |
House prices vary from place to place and are usually high ________ there are famous schools.
| A．when | B．since |
| C．where | D．whether |
It will be another 50 years ______ our country is expected to reach the level of a medium developed country.
| A．since | B．before |
| C．that | D．when |
Jerry has promised to keep the secret, so he won't tell anyone ________ asked to.
| A．until | B．now that |
| C．unless | D．even though |
________ you have to do the job, you should try your best to do it well even though it may be very difficult for you.
| A．Since | B．While |
| C．Unless | D．Though |
Besides, ________ well it is translated, the spirit of the original work is lost.
| A．no matter how | B．no matter what |
| C．no matter when | D．no matter where |
He never thought that his success came ________ he least wanted it.
| A．until | B．since |
| C．when | D．while |
Some experts have said that ________ children believe they can succeed, they will never become totally confident of themselves.
| A．if | B．since |
| C．once | D．unless |