— Li Ming looks very weak.
— __________. He has not yet recovered from the illness.
| A．So he is | B．So he does | C．So is he | D．So does he |
It was found that although the girl could perceive things with her fingers, this ability ceased _____ her hands were wet.
| A．the moment when | B．the moment | C．in that moment | D．before |
______ you understand this rule, you’ll have no further difficulty.
| A．while | B．Once | C．Though | D．Unless |
It will not be long _____man can harness the solar energy and make it serve mankind.
| A．since | B．before | C．when | D．after |
Doing your homework is a sure way to improve your test scores, and this is especially true______ it comes to the classroom tests.
| A．before | B．as | C．since | D．when |
Substances will expand or contract ______ heated or cooled, but this is not the case with water.
| A．when they will be | B．if they will be |
| C．as they being | D．when |