单项选择题
A.proper break-in wear
B.improper break-in wear
C.relocation of the overlay flashing
D.water contamination of the lube oil system
单项选择题 If a diesel engine turned over freely but failed to start, the cause could be （）
单项选择题 If it becomes necessary to cutout an individual cylinder of a large, low-speed, main propulsion diesel engine, the fuel to that cylinder should be secured and its （）
单项选择题 The satisfactory operation of diesel engine exhaust valves usually depends on（）