栓剂油脂性基质
A．蜂蜡 B．羊毛脂 C．甘油明胶 D．半合成脂肪酸甘油酯 E．凡士林
参考答案：D
A．I= ，从上向下
B．I= ，从上向下
C．I= ，从下向上
D．I= ，从下向上
The number of articles published on smoking _____ amazing.[ ]
a. is
b. are
c. were
d. have been
