单项选择题
A.two strokes of the piston B.four strokes of the piston C.one revolution of the crankshaft D.four revolutions of the crankshaft
The purpose of the skirt or trunk in four-stroke cycle ...
单项选择题The purpose of the skirt or trunk in four-stroke cycle engines is to act in a similar manner to a （）.
A.crosshead B.crown C.piston rod D.connecting rod
Medium speed engines have a （） power to weight ratio th...
单项选择题Medium speed engines have a （） power to weight ratio than the slow speed two strokes, but due to the higher speeds tend to have （） maintenance intervals.
A.higher；reduced B.higher；increased C.lower；reduced D.lower；increased
（） allows the engine to be placed wherever is most suit...
单项选择题（） allows the engine to be placed wherever is most suitable, as they no longer have to be aligned with reduction gearing and shafting as is the case with conventional installations.
A.Diesel engine propulsion B.Diesel electric propulsion C.Steam engine propulsion D.Gas turbine propulsion
