A.一個 B.二個 C.三個 D.四個
A.發(fā)病率 B.性別 C.年齡段 D.居住地區(qū)
A.Analyze→Compare Means→Means B.Analyze→Compare Means→One-Samples T Test C.Analyze→Compare Means→Independent-Samples T Test D.Analyze→Compare Means→Paired-Samples T Test