抗体一般是（）
A.单价的
B.双价的
C.三价的
D.四价的
E.五价的
参考答案：B
The girl __________ sing in the next room last Sunday.[ ]
A. heard to
B. is heard to
C. was heard
D. was heard to
癫痫患者服用抗癫痫药最切忌：（）
A.用药剂量太小
B.同时合用两种药
C.只在夜间服
D.药物价格太高
E.突然停药
