secondary stem villus次级: secondary绒毛: fine hair; down; lana; pubes ...干: trunk; main part初级绒毛干: primary stem villus三级绒毛干: tertiary stem villus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:次级绒毛干，即可在微信中查询翻译
