—Three _____ injured students died in a hospital ineast China's Jiangsu Province last year.  

—Sorry  to hear  that. But our government ______ much about the school bus safety management.[ ]

A. serious; did          

B. bad; did

C. seriously; has done    

D. badly; was done

龈下菌斑主要为

A．革兰阴性厌氧者

B．革兰阳性球菌

C．需氧菌

D．衣原体

E．以上都不对