单项选择题
A.fuel oil vapor at the sludge tank vent
B.unburned fuel vapors in the scavenge air receiver
C.lube oil vapors in the crank case
D.lube oil vapors in the engine room
单项选择题 Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished （）.
单项选择题 To prevent vibration damage to the fuel supply line of a diesel engine, you may use （）.
单项选择题 When the prime movers of two paralleled generators are equipped with mechanical- hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will （）.