单项选择题
Failure to open the diesel engine test cocks after a long period of shutdown, prior to starting may result in （）
A.an air bound fuel system B.damage to cylinder heads and pistons C.excessive fuel injection D.excessive air valve lift
单项选择题 Heat damage to fuel injection nozzles can be prevented by avoiding （）
单项选择题 Critical speed in diesel engines occurs when engine torque pulsations become （）
单项选择题 Air receivers installed in starting air systems are to be （）.
