单项选择题
A.is always less than 100% B.is always more than 100% C.is always equal to 90% D.is always less than 90%
The marine diesel engine is a type of diesel engine use...
单项选择题The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.
A.principle B.principal C.cause D.case
The majority of medium speed and high speed marine dies...
单项选择题The majority of medium speed and high speed marine diesel engines for main or auxiliary drive operate on the （） cycle.
A.two-stroke B.four-stoke C.long-stroke D.short-stroke
The main moving parts of a diesel engine consist of the...
单项选择题The main moving parts of a diesel engine consist of the （） and the pistons.
A.bedplate, connecting rods B.crankshaft, the connecting rods C.frames, crossheads D.crankshaft, the cylinder
