单项选择题
A diesel engine cylinder head can crack as a result of （）
A.a leaking seal ring B.heat transfer from exhaust valves C.restricted cooling passages D.overheated intake valves
单项选择题 In large, low-speed, main propulsion diesel engine, position ring groove wear usually occurs at the（）
单项选择题 Diesel engine blow-by is the leakage of combustion gases past the （）
单项选择题 In a diesel engine, blow-by is a result of combustion gases leaking into the crankcase past the （）
