A.空白對(duì)照B.歷史對(duì)照C.標(biāo)準(zhǔn)對(duì)照D.安慰劑對(duì)照E.實(shí)驗(yàn)對(duì)照
A.歷史對(duì)照B.空白對(duì)照C.標(biāo)準(zhǔn)對(duì)照D.安慰劑對(duì)照E.自身對(duì)照
A.減少抽樣誤差B.減少實(shí)驗(yàn)例數(shù)C.提高檢驗(yàn)效能D.提高檢驗(yàn)準(zhǔn)確度E.保持各組的非處理因素均衡一致