stratified sampling成: accomplish; succeed层: I storey; tier; stratum抽样: sample; sampling; specimen; ...二层抽样: two-stage sampling分层抽样法: stratified sampling method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:成层抽样,即可在微信中查询翻译