检疫的特殊要求是持有效卫生证书的国际航行船舶在抵港前( )小时，通过船舶公司或船舶代理向港口或锚地所在地检验检疫机构以电报形式报告。

A．on
B．in
C．back
D．/

A．certificate of measurement; certificate of damage
B．certificate of radioactivity; certificate of damage
C．certificate of radioactivity; certificate of cleanliness
D．certificate of origin; certificate of cleanliness