单项选择题
Pyrometers commonly found on diesel engine exhaust systems, consist of（）
A.pyrostats and a voltmeter B.a gas-filled bellows, a tube and a pressure gauge C.thermocouples and a voltmeter D.ammeters and thermocouples
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 （）
单项选择题 Diesel engine air start system check valves are opened by （）
