"引药归经"是指炮制对药物哪项的影响（）
A.作用趋向
B.作用部位
C.四气
D.五味
E.毒性
参考答案：B
_____ of the good results of the exam, the teacher felt very happy.
A．informed
B．told
C．acknowledged
D．convinced
牙尖部牙釉质最厚为( )
A．2～2.5mm
B．6mm
C．4～5mm
D．1mm
E．8mm
