I have also witnessed a player reacting to his opponent蒺s intentional and illegal blocking by deliberately hitting him with the ball as hard as he could during the course of play. (05.6 Passage 1)
分析主干:I have (also) witnessed a player reacting
reacting 在句中是现在分词,作宾语a player 的补语;by... hitting...是reacting 的方式状语,hitting 作介词by 的宾语。as hard as he could 是比较结构,表示“尽力”。