记叙文的写作结构 — 英语词汇题

阅读下面的句子，它们摘自一篇关于 Wilma 的记叙文：①Her coach trained her hard every day, but her leg hurt badly at times. ②In 1960, Wilma won three gold medals at the Olympic Games. ③Wilma was born into a poor family and could not walk before she was five. 请将三个句子的序号按记叙文结构的 beginning、middle、ending 的顺序排列（用①②③回答）。