单项选择题
A.must replace B.must to be equipped C.has to be repaired D.have to be renewed
The piston rings are manufactured with a diameter （） th...
单项选择题The piston rings are manufactured with a diameter （） the bore of the cylinder.
A.larger than B.smaller than C.equal to D.none of the above
The piston ring grooves for a standard engine are （）A.c...
单项选择题The piston ring grooves for a standard engine are （）
A.chromium-plate against wear B.anti-corrosion treated C.white metal lined against wear D.flame hardened against wear
The piston moving up and down keeps the crankshaft （）.A...
单项选择题The piston moving up and down keeps the crankshaft （）.
A.to revolve B.revolved C.revolving D.to be revolved
