单选题The satisfactory operation of diesel engine exhaust valves usually depends on（）Athe proper back pressureBthe cooling water temperatureCcorrect timing and proper seatingDaccurate metering and the exhaust temperature
单选题
The satisfactory operation of diesel engine exhaust valves usually depends on（）
A
the proper back pressure
B
the cooling water temperature
C
correct timing and proper seating
D
accurate metering and the exhaust temperature
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