【C9】A．WhileB．IfC．UnlessD．Meanwhile

A．becauseB．althoughC．unlessD．so

【C9】A．whenB．ifC．untilD．after

【C9】A．ThereforeB．AndC．OtherwiseD．Meanwhile

【C4】A．SlowlyB．ImmediatelyC．CarefullyD．Meanwhile

Doctors won t operate on the patient______absolutely necessary.A．whenB．ifC．unlessD．though

【C9】A．becauseB．ifC．thoughD．when