决定Ig型和亚型的部位（）
A.V区
B.C区
C.绞链区
D.重链
E.轻链
参考答案：E
The following three concepts are essential to the OSI model:service,interface and
A． networks
B． applications
C． protocols
D． layers
处方药可以采用开架自选销售方式
