Unable to move because of the injury in his leg, Jack was forced to wait _____ he was, wrapped

in Michael's jacket.[ ]

A. who

B. where

C. what

D. when

下列不属于海水提升泵的主要组成部分的是（）。

A、潜水电机

B、电机冷却水膨胀水箱

C、闭式叶轮

D、活塞