单项选择题
A.once each crankshaft revolution B.twice each crankshaft revolution C.every other crankshaft revolution D.every fourth stroke
Centrifugal pumps have what advantage(s) over reciproca...
单项选择题Centrifugal pumps have what advantage(s) over reciprocating pumps?（）.
A.They are less expensive B.They are smaller for equivalent pumping ability C.They pump more cargo in less time D.All of the above
Cargo pump relief valves are piped to the（）.A.cargo pum...
单项选择题Cargo pump relief valves are piped to the（）.
A.cargo pump pressure gauges B.crossover lines interconnecting two pumps C.suction side of pumps D.atmosphere through pump vents
As the propeller turns，voids are formed on the trailing...
单项选择题As the propeller turns，voids are formed on the trailing and leading edges of the propeller blades causing a loss of propulsive efficiency，pitting of the blades，and vibration. These voids are known as（）.
A.advance B.cavitation C.edging D.slip
