单项选择题
A.the crosshead B.the crankshaft C.large end D.the piston bosses
Generally the function of lubrication is to form of a f...
单项选择题Generally the function of lubrication is to form of a film of lubricant between any two surfaces that have relative （）, so that surfaces dont get touch with each other.
A.gravity B.motion C.ratio D.density
Fuels of high quality with their earlier ignitions will...
单项选择题Fuels of high quality with their earlier ignitions will cause higher （）pressure in cylinders of a diesel engine.
A.compression B.maximum C.rated D.oil
Fuel pump index is （）.A.the viscosity indexB.the fuel o...
单项选择题Fuel pump index is （）.
A.the viscosity index B.the fuel oil contents C.the starting speed D.the reading at the rack
