At that time he looked angry because his son______computer games all the afternoon

A．played

B．was playing

C．has played

D．had been playing

下列修改最有必要的是( )。

A．将发文字号移至标题正下方

B．删除文中“基本上”

C．将文中的“你校”改为“贵校”

D．将“现经我局认真研究，作出如下批复”改为“现批复如下”