问题详情

A centrifugal bilge pump requires priming _____.

A.primarily to lubricate the shaft seals

B.due to the inability of this type of pump to lift water to cover the suction (eye) of the impeller

C.to initially unload the pump by having its head pressure equal to discharge pressure

D.in order to overcome the potential energy of water in the discharge line

请帮忙给出正确答案和分析，谢谢！