单项选择题
A.oil B.sea water C.air D.fresh water
In a four-stroke engines the camshaft rotates at （）.A.h...
单项选择题In a four-stroke engines the camshaft rotates at （）.
A.half the engine rotational speed B.twice the engine rotational speed C.the engine rotational speed D.four times the engine rotational speed
In a diesel engine, fuel must be broken up into a spray...
单项选择题In a diesel engine, fuel must be broken up into a spray of fine droplets to （）.
A.increase its quality B.obtain complete burning C.reduce its weight D.all of the above
In a complete oil/water separator, more oil will separa...
单项选择题In a complete oil/water separator, more oil will separate out onto the underside of these plates and travel outwards until it is free to rise into the oil collecting space Whats the meaning of "it" in the sentence above?（）
A.a separator B.oil C.water D.an oil collecting space
