Seoul is the heart of an urban area of more than 25 million people — among the largest in the world — and like any 21st-century megalopolis, it is impossible to grasp as a single entity.

首尔位于一片人口超过2500万的都市区的中心，位列世界最大城市之一，和其他的21世纪巨型城市一样，你无法把首尔看成某种单一的存在。

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With the metropolitanization in US in the early 20~(th) century, Megalopolis represented typically by the Northeast seaboard Megalopolitan area in US emerged.

20世纪初期美国大都市区化完成后，随即出现了以东北部大都市带为典型代表的大都市带。

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