—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

（6分） 如图所示，一个重为100 N的小球被夹在竖直的墙壁和A点之间，已知球心O与A点的连线与竖直方向成θ角，且θ＝60°，所有接触点和面均不计摩擦．试求小球对墙面的压力F₁和对A点压力F₂.