A.分層抽樣 B.簡單隨機(jī)抽樣 C.整群抽樣 D.等距抽樣
A.時(shí)間顛倒測試 B.因子顛倒測試 C.平衡測試 D.循環(huán)測試
A.90% B.90.9% C.110% D.111.1%