现患病例—新发病例偏倚又称
A．Neyman偏倚B．选择偏倚C．Berkson偏倚D．信息偏倚E．混杂偏倚
参考答案：A
The stream________during the hot summer, but it is full of water in spring.
A．dries up
B．dries out
C．dries off
D．dries on
祛风湿，强筋骨的药物是（）
A.狗脊
B.香加皮
C.千年健
D.鹿衔草
E.牛膝
