vaccines (疫苗) are complex biologic products. strong management and if not correctly, vaccines can lose same of their effectiveness.
A. requiring; handled B. requiring; handling
C. required; handling D. required; handled
vaccines (疫苗) are complex biologic products. strong management and if not correctly, vaccines can lose same of their effectiveness.
A. requiring; handled B. requiring; handling
C. required; handling D. required; handled
A