单项选择题
Low compression pressure in a diesel engine can be caused by（）
A.improperly seating intake valves B.leaking cylinder liner seal rings C.late fuel injection timing D.carbon deposits on the piston
单项选择题 During the power stroke of a four-stroke/cycle diesel engine, most of the side thrust of a trunk-type piston is absorbed by the（）
单项选择题 A pyrometer is an instrument commonly used to measure（）
单项选择题 Worn main bearings in a diesel engine can result in （）
