—Is Johnson in the classroom?

—Maybe not. I saw him _______ the dining hall just now.        [ ]

A. entering          

B. enter            

C. to enter

针对材料中提出的“网络暴力”问题，写一篇论述文。要求：观点鲜明，内容充实，结构完整，语言流畅，字数掌握在900字左右。