下列哪些预防措施是针对传染病接触者的（）。
A.住院隔离
B.留验
C.应急接种
D.药物预防
E.医学观察
参考答案：B, C, D, E
I can’t think why he that; it was my fault.
A．would have said
B．should have said
C．ought to have said
D．might have said
形状特殊的孔型或轧件在轧制过程中迫使金属有较大的宽展，这种宽展称为（）。
