[矿业] 分层取样法 stratified random sampling method: 分层随机抽样法stratified sampling method: 分层抽样法sampling stratified: 分层抽样stratified sampling: 成层抽样; 分层抽样品; 分层取样area stratified sampling: 区域分层抽样下载手机词典可随时随地查词查翻译