单选题It was _____ computer&nbs

问题补充：

单选题Itwas_____computergamesthatcosttheboyalotoftimethatheoughttohavespentonhislessons.A.to have playedB.playingC.playedD.having played

答案：

B解析此句是强调句型，强调句子的主语playing computer games。