单项选择题
One of the consequences in continuing to operate a centrifugal bilge pump with the discharge valve closed, is that the （）.
A.motor overload will open B.relief valve will open C.pump will overheat D.motor will overheat
单项选择题 Which of the following statements is correct concerning a typical shipboard multi-coil refrigeration system?（）
单项选择题 The basic function of the centrifugal pump impeller is to （）.
单项选择题 Excessive oil foaming in the crankcase of a refrigeration compressor can result in （）.
