urbanization can only exist as a temporary phase in the development of human society. 城市化仅可以作为人类社会发展的一个短暂阶段而存在。

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Urbanization initially promotes the development of human society, but once it reaches a certain point, it will hinder or even destroy human civilization.
In other words, urbanization can only exist as a temporary phase in the development of human society.

城市化，在前期会促进人类社会的发展，但是一旦发展到一定程度，城市化将会阻碍，甚至催毁人类社会的文明。
换句话说，城市化仅可以作为人类社会发展的一个短暂阶段而存在。