单项选择题
A.electronic ignition system
B.compression of air by the piston
C.friction in the fuel injector
D.fuel oil bearing system
单项选择题 Diesel engine crankshaft deflection readings are generally taken at four crank positionsGood engineering practice requires the deflection gage or indicator to be（）
单项选择题 Fuel oil injected into the cylinder of a diesel engine just after the piston passes top dead center, will（）
单项选择题 Diesel engine injection lag is caused by（）