A．(A) Because they want to feel the thrill and excitement.

B．(B) Because they are tired of modern-day university life.

C．(C) Because they are interested in the scientific experiment.

D．(D) Because they find that it is the best way to reduce weight.

（）是指泵能同时提供高压和低压的工作状况。

A.手抬机动消防泵组

B.引水时间

C.吸深

D.高低压联用工况