善清上焦之火的药物是（）
A.黄连
B.黄芩
C.黄柏
D.苦参
E.栀子
参考答案：B
— It's 8 o'clock in the evening. What's your uncle doing?
— I think he ____ TV.[ ]
A. watch
B. watches
C. watching
D. is watching
沉降性颗粒物的粒径一般为（）
A．5um～10um
B．>101um～50um
C．>50um～75um
D．>75um～100um
E．>100um
