词汇	two ring piston
释义	two ring piston 双环式活塞
随便看	elliptical trace elliptical track elliptical trainer elliptical trainers elliptical trajectory elliptical transfer orbit elliptical translation elliptical traveler elliptical traveller elliptical triangle functions elliptical trochoidal wave elliptical truncation elliptical tube elliptical tube evaporative cooler elliptical tube opening elliptical tubesheet elliptical type rotor elliptical type weight elliptical-type weigth elliptical tyre elliptical valve diagram ellipticalvault elliptic al vault elliptical velocity elliptical vessel