单项选择题
Excessive valve lash in an auxiliary diesel engine will cause the valves to open（）
A.later and close sooner B.sooner and close later C.sooner and close sooner D.later and close later
单项选择题 Pyrometers commonly found on diesel engine exhaust systems, consist of（）
单项选择题 Low compression in a diesel engine can be caused by （）
单项选择题 In a four-stroke cycle diesel engine the intake valves open （）
