单项选择题
A.atmosphere B.the fresh water C.compressed air D.chemical compounds
The lubricating oil is pumped from the drain tank, very...
单项选择题The lubricating oil is pumped from the drain tank, very often with （） in the suction line.
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
