ringless piston无环活塞
Ringless compass无环罗盘
RINGLESS HONEY FUNGUS假蜜环菌
Inner Ringless Roller Bearing无内圈滚柱轴承;无内圈滚子轴承
brushless and ringless starter无刷无环起动器
Other ringless multi-amines and derivative其他无环多胺及其衍生物