短語詞組短語Pull Back Power ring 倒后擦發(fā)條BACK UP RING KIT 備份環(huán)套件;備份圓環(huán)套件back support ring 后支承環(huán)Back up ring 支承環(huán)back sealing ring 后密封環(huán)back moving ring 回位彈簧back locating ring 后定位環(huán)back contact ring 靜接點彈簧 返回 back ring