I didn' t manage to do it _____ you had explained how.
| A．until | B．unless | C．when | D．before |
The officers narrowly escapedin the hot battle.
| A．have killed | B．to kill | C．to be killed | D．being killed |
We have made _____ a rule ______ in the office.
| A．this, not to smoke | B．it, smoking | C．it, to not smoke | D．it, not to smoke |
. I didn’t take part in _____ singing competition last Sunday because he was afraid of losing _____ face.
| A．a; the | B．/;/ | C．the; a | D．the; / |
The sports meet, originally due to be held last Friday, finally ______ because of the terrible weather.
| A．put off | B．broke down | C．called off | D．set off |
For those who work with their brains, exercise is ______.
| A．of very value | B．of great valuable | C．great valuable | D．very valuable |