单项选择题
A.by an fuel valve B.through an inlet valve C.with an exhaust valve D.from an outlet valve
In the sentence “In some designs the cylinder oil is ti...
单项选择题In the sentence “In some designs the cylinder oil is timed so that the oil injects only on the piston ring belt, the "piston ring belt" means （）.
A.piston crown B.piston ring groove C.piston skirt D.piston ring area
In the four-stroke engine, it takes （） to make one powe...
单项选择题In the four-stroke engine, it takes （） to make one power stroke.
A.one propulsion B.two propulsions C.two revolutions D.one revolution
In the event of the cylinder starting valve leakage （） ...
单项选择题In the event of the cylinder starting valve leakage （） would pass into the air pipes and ignite the oil deposited.
A.cooling water B.vapor from the boiler C.starting air D.hot gases
