13. ___ had they reached the 30th floor ____ they realized that they had forgotten to take the key.
| A．Hardly; than | B．Hardly; when | C．No sooner; when | D．No sooner; then |
It's much easier to make friends __________ you have similar interests.
| A．unless |
| B．when |
| C．even though |
| D．so that |
Experts believe __________ people can waste less food by shopping only when it is necessary.
| A．why |
| B．where |
| C．that |
| D．what |
Food supplies may __________ towards the end of the trip, so we can't waste any food.
| A．run out |
| B．run up |
| C．run into |
| D．run away |
The watch was very good, and he __________20 percent down for it.
| A．paid |
| B．cost |
| C．bought |
| D．spent |
I got to the office earlier that day，__________ the 7：30 train.
| A．caught |
| B．to have caught |
| C．to catch |
| D．having caught |