桑叶、菊花同用的方剂是（）
A.银翘散
B.桑杏汤
C.天麻钩藤饮
D.羚角钩藤汤
E.仙方活命饮
参考答案：D
3×8=24，选用的乘法口诀是[ ]
A．三八二十四
B．二八十六
C．四八三十二
Which of the following statements about hypothesis testing is TRUE A Type Ⅱ error is the probability of:（）
A. rejecting a true null hypothesis.
B. rejecting a true alternative hypothesis.
C. failing to reject a false null hypothesis.
