cupped washer凹: low-lying area; depression垫圈: grommet; carrier ring; clout ...凹垫层宝石: hollow doublet垫圈: 垫圈[牧] (给牲畜的圈铺垫干土碎草等) bed down the livestock; spread earth in a pigsty, cowshed, etc.板垫圈: plate washer下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:凹垫圈，即可在微信中查询翻译
