A               

题目分析：考查固定句型。句意：我的同学们十分兴奋了解到英语演讲比赛的好结果。原句话为my classmates were so excited to know the good result of the English speech competition.，故选A项。Be excited to do 某人很兴奋去做某事，故选A项          

考点 : 考查固定句型