单项选择题
A pyrometer is an instrument used to measure the temperature of the diesel engine（）
A.exhaust B.fuel oil C.cooling water D.cylinder liner
单项选择题 Low compression pressure in a diesel engine can be caused by（）
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（）
