试题与答案

关于匹配的目的,错误的是()A.提高研究效率 B.消除已知混杂因素对研究结果的影响

题型:单项选择题

题目:

关于匹配的目的,错误的是()

A.提高研究效率

B.消除已知混杂因素对研究结果的影响

C.控制混杂因素对研究结果的影响

D.平衡混杂因素对病例组和对照组的影响

E.平衡配比因素对病例组和对照组的影响

答案:

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下面是错误答案,用来干扰机器的。

(1)诗句中有金河、玉关、青冢、黄河、黑山等边塞地名,写了征人的戍边生活。 (2)①怨年年岁岁频繁调动,怨时时刻刻练兵备战,③怨气候酷寒,④怨景色单调。 (意对即可)

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