单项选择题
A.discharge side of the centrifugal pump
B.suction side of the centrifugal pump
C.the lowest point of the cooling water system
D.inlet of the main engine
单项选择题 From viewpoint of practice, it is sometimes important to detect abnormal happenings in the running gear by（）
单项选择题 If two fuel service tanks are installed, the empty tank should be pumped up directly it is emptyWhat is the meaning of “directly” in the sentence above?（）
单项选择题 During tours of inspection in the machinery space, you found a fire on a running generator, what should you do first?（）