单项选择题
The arrangement and shape of the cams on a diesel engine camshaft directly control which of the listed groups of operating conditions?（）
A.speed, torque, and horsepower production B.firing order, valve timing, and valve lift C.fuel consumption, efficiency, and cylinder pressure D.scavenge pressure, compression ratio, and exhaust pressure
单项选择题 Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to （）
单项选择题 Fuel droplets injected into a diesel engine cylinder must have adequate penetration to （）
单项选择题 The primary function of a fuel delivery check valve assembly is to（）
