保护易感人群的主动免疫措施是

A．接种抗毒素

B．注射丙种球蛋白

C．接种疫苗、菌苗、类毒素

D．注射高价免疫球蛋白

E．加强营养

In the informal meeting the exporter learned that the importer was interested purchase rather than prepacked sets of 12.

A．in bulk

B．in essence

C．at random

D．at ease