单项选择题 With （） unit the timing of fuel injection of an engine can be regulated automatically.

单项选择题 With supercharging a larger mass of air is supplied to the cylinder by blowing it in under pressure, which is the best means to （） of the engine.

单项选择题 Whilst the engine is turning, check to see that no water is leaking into the crankcase, scavenge air belt, or from （）.