单选题Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to（）Afacilitate bi-directional operationBprovide the greatest pump efficiencyCprevent pump clogging from marine growthDprevent cavitation at the pump outlet
单选题
Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to（）
A
facilitate bi-directional operation
B
provide the greatest pump efficiency
C
prevent pump clogging from marine growth
D
prevent cavitation at the pump outlet
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