[解析]
(1)D.细节理解题.根据第二段"You'd be surprised at how many people donate money around the time of the marathon"可知,作者参加马拉松的目的是为慈善机构募捐.故选D.
(2)A.细节理解题.根据第二段" It was my first marathon.I did my research,made a plan and put it up on my wall and crossed an item off every time I went for a run."可知,适当的训练计划对参加马拉松很重要.故选A.
(3)D.细节理解题.根据最后一段"But that's fine.I know I've already achieved something rather special that I can't stop talking about"可知,马拉松比赛是很令作者激动的,才让作者说得停不下来.故选D.
(4)C.细节理解题.根据最后一段"But that's fine.I know I've already achieved something rather special "可知,参加马拉松是作者引以为傲的一件事情.故选C.