积液LD/血清LD比值为多少时,考虑为良性积液() ["<0.6","<0.5",">0.6",">0.5",">1"]
有关混杂因素和混杂偏倚的说法正确的是() ["有混杂因素存在一定会产生混杂偏倚","混杂因素主要指年龄、性别、职业这些人口学特征因素","混杂偏倚引起的继发关联是典型的混杂偏倚类型,而引起的间接关联则不是混杂偏倚","在分析阶段控制混杂的方法多采用多元分析,不仅能分析暴露因素的效应也能估计混杂因素的效应","暴露因素和混杂因素的概念是绝对的,有些因素只能是暴露因素,而另一些因素一定是混杂因素"]
过失误差
检查尿中管型(Cast)最适宜标本为() ["首次晨尿标本","餐后尿标本","8小时尿标本","随机尿标本","24小时尿标本"]
修约
公差