单选题 When the Erie Canal was built in the 1820's, it was the engineering {{U}}marvel{{/U}} of its time.
【正确答案】 A
【答案解析】[分析] 名词辨析。 marvel奇迹；wonder奇迹，惊奇；dispute争论，辩论，争吵；frustration挫败，挫折，受挫，model样式，模范，典型，因此选项A为答案。