单项选择题
A.inlet valves B.exhaust valves C.emergency valves D.run-return valves
The successful operation of any engine or machine and （...
单项选择题The successful operation of any engine or machine and （） depend on effective lubrication.
A.their no trouble period B.their freely trouble period C.its free trouble life D.its trouble-free life
The starting of a marine diesel engine is generally car...
单项选择题The starting of a marine diesel engine is generally carried out with the assistance of （）.
A.compressed air B.electricity C.hydraulic oil D.compressing air
The starting air system usually has （） to prevent start...
单项选择题The starting air system usually has （） to prevent starting if anything is not in order.
A.stop valves B.interlocks C.non-return valves D.air vents
