单项选择题
A.a cooling system B.a lubrication oil system C.an electric system D.an injection system
Oil will lubricate these parts （） effectively than wate...
单项选择题Oil will lubricate these parts （） effectively than water.
A.much B.more C.most D.less
Oil pressure in the lubrication system is （） the static...
单项选择题Oil pressure in the lubrication system is （） the static sea water head to ensure that sea water （） the stem-tube.
A.lower than；can lubricate B.lower than；can cool C.higher than；can enter D.higher than ；cannot enter
Oil is supplied to the cylinder wall and （） by means of...
单项选择题Oil is supplied to the cylinder wall and （） by means of mechanical lubricators.
A.the cylinder cover B.the piston rings C.the piston crown D.the piston skirt
