He had to pause from time to time to wipe the sweat from his forehead, because the air-conditioning system
It suddenly occurred to him ________ he had left his keys in the office.
| A．whether |
| B．where |
| C．which |
| D．that |
It was a real race ________ time to get the project done. Luckily, we made it.
| A．over |
| B．by |
| C．for |
| D．against |
—How far can you run without stopping?
—_________. I’ve never tried.
| A．Don’t mention it |
| B．That’s all right |
| C．I have no idea |
| D．Go ahead |
A serious study of physics is impossible ________ some knowledge of mathematics.
| A．against |
| B．before |
| C．beyond |
| D．without |
—I’m afraid you have the wrong number.
—Sorry! ________.
| A．See you later |
| B．I didn’t know that |
| C．Hold on, please |
| D．I hope I didn’t bother you |