She teaches English in a school. She is a . [ ]
A. doctor
B. teacher
C. nurse
答案:B
协同凝集反应,IgG与sPA的结合部位是
A.VHB.VLC.FabD.FcE.绞链区
风险管理是研究风险发生的( )。
A.因素
B.规律
C.幅度
D.损失