Why are some public transportation modes very popular, such as the subway? This question explores public transportation modes, especially why mass transit tools like the subway are widely welcomed. When answering, one can analyze from various perspectives such as convenience, affordability, environmental friendliness, and give examples of how these modes of transportation meet the travel needs of modern urban residents.

为什么一些公共交通方式很受欢迎，例如地铁？这个问题探讨了公共交通方式，尤其是地铁等大众交通工具为何受到广泛欢迎。回答时，可以从便捷性、经济性、环保性等多个角度分析，举例说明这些交通方式如何满足现代城市居民的出行需求。