单项选择题
A.a filter B.a strainer C.a magnetic filter D.a fine strainer
The lube oil in the bearings is drawn from a （）, usuall...
单项选择题The lube oil in the bearings is drawn from a （）, usually located in the bedplate.
A.tank B.sump C.vessel D.bottle
The lowest ring of a piston is （）.A.a coil springB.a se...
单项选择题The lowest ring of a piston is （）.
A.a coil spring B.a sealing ring C.an oil distributor ring D.main seal ring
The lower end of each piston rod is reduced in diameter...
单项选择题The lower end of each piston rod is reduced in diameter to fit a bore in （）.
A.the crosshead B.the journals of the crosshead C.the crosshead shoes D.the guides
