Upper and lower piston rings are arranged inside a piston gaseousring groove, and openings on the two-piece piston rings are mutually staggered.
在一个活塞气环槽内设有上下二片活塞环,二片活塞环上的开口相互错开。
2
With his 20-power telescope and with his eyes in bad shape he might have mistaken Saturn's gaseousring to surmise that it was formed of one planet with two moons as satellites.