单项选择题
A.crankshaft B.camshaft C.piston rod D.rack and pinion
The pistons are cooled by oil supplied from the forced ...
单项选择题The pistons are cooled by oil supplied from the forced （） system.
A.fresh water B.sea water C.lubrication D.fuel oil
The piston supporting body is mainly subjected to （） st...
单项选择题The piston supporting body is mainly subjected to （） stress.
A.pushing B.centrifugal C.stretch D.compressive
The piston rings if found worn out （） and supplied by s...
单项选择题The piston rings if found worn out （） and supplied by shipchandler.
A.must replace B.must to be equipped C.has to be repaired D.have to be renewed
