单项选择题
A.cylinder heads B.exhaust valves C.scavenging air D.injectors
Lube oil pumps taking suction from the sump of most sma...
单项选择题Lube oil pumps taking suction from the sump of most small marine engines are usually （）.
A.of the diaphragm type B.of the centrifugal type C.of the positive displacement type D.independently driven by electric motors
Fuel oil begins injection into the cylinder of a four-s...
单项选择题Fuel oil begins injection into the cylinder of a four-stroke/cycle diesel engine during the （）.
A.intake stroke B.exhaust stroke C.power stroke D.compression stroke
Telescopic pipes to the piston of a large slow-speed ma...
单项选择题Telescopic pipes to the piston of a large slow-speed main propulsion diesel engine are designed to prevent （）.
A.excessive crankcase pressure B.excessive lube oil temperature C.contamination of the lube oil by water D.contamination of the cooling water by lube oil
