13. The struggle against the bird flu and the suffering _________ brought about have become a big concern across the world.

A．which has

B．it is

C．it has

D．what is

根据我国宪法和有关组织法的规定，下列( )属于我国社会主义法的渊源。

A．地方性法律

B．自治区条例和单行条例

C．特别行政区的法律

D．国际条约

E．行政法规