He____know the answer, but I’m not sure.
A. maybe B. may be C:may D. must
He didn’t go to bed _______ his mother came back.
| A．until | B．if | C．as soon as | D．when |
It is ___________ to hold the water.
| A．strong enough | B．enough strong |
| C．too strong | D．to strong |
You must have breakfast, _________ you may have a stomachache.
| A．or | B．and | C．but | D．so |
It is difficult ________me _______ English well. But I’ll study harder.
| A．to, learn | B．for, learning |
| C．for, to learn | D．to, to learn |
Don’t swim here ,or you may be __________.
| A．in danger | B．danger | C．safe | D．well |