单项选择题
A.cutting out individual injectors and noting engine performance
B.checking lube oil temperature
C.checking cam position
D.using a timing light
单项选择题 What harmful condition can result if a diesel engine is operated at very light loads for long periods of time?（）
单项选择题 Turbocharged four-stroke/cycle diesel engines utilize valve overlap for（）.
单项选择题 Operating a propulsion diesel engine at less than 30% of designed normal load for prolonged periods will result in （）.