活塞式压缩机在吸气压力不变时，降低排气压力，其功率消耗将（）。
A.增加
B.降低
C.不变
D.为零
参考答案：B
--Were you in time for the meeting?
-- If I _________earlier, I would have .
A．was told
B．had been told
C．were to be told
D．should be told
