In time of serious accidents, _______ we know some basic things about first aid,we can save lives.
| A．whether | B．until |
| C．if | D．unless |
相关试题
Speaking of all the songs he has written, I think this is probably his _______ one.
| A．better-known | B．well-known |
| C．best-known | D．most-known |
I would appreciate it _______ you call back this afternoon for the doctor’s appointment.
| A．that | B．if | C．which | D．whether |
We can never expect _______ bluer sky unless we create _______ less polluted world.
| A．a; a | B．a; the | C．the; a | D．the; the |
We all know that, _______, the situation will get worse.
| A．not if dealt carefully with | B．if not carefully dealt with |
| C．if dealt not carefully with | D．not if carefully dealt with |
推荐套卷
粤公网安备 44130202000953号