单项选择题
Exhaust pipes for separate diesel engines can be combined only when （）
A.space limitations prevent separately run pipes B.the engines are small auxiliary units C.they are arranged to prevent gas backflow to each engine D.a waste heat boiler is installed
单项选择题 An increase in crankcase pressure generally indicates（）
单项选择题 Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）
单项选择题 If the relief valve on a diesel engine cylinder lifts, the cause could be due to （）
