单项选择题
A.tape face B.tapered face C.surface D.thinner face
The needle valve in the injector （） at a pre-set pressu...
单项选择题The needle valve in the injector （） at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.
A.will lift B.will be lifted C.will close D.will be closed
The needle valve in a fuel valve will （） when the fuel ...
单项选择题The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.
A.be jammed B.be opened C.be seated D.be broken
The most common cause of lowering the crankcase lube oi...
单项选择题The most common cause of lowering the crankcase lube oil flash point is （）.
A.more water contents B.contamination with fuel oil C.higher temperature D.sufficient cooling of oil mist
