A:an art much a
B:much an art a
C:as an art much a
D:as much an art a
35÷7____ 6 8×6____48 7×7____47 40÷5____7
为了预防和控制甲型H1N1流感,国家抓紧研制接种并免费提供给人们注射.则该过程程中注射的主要物质及采取的措施分别称为( )