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.

為什麼一些公共交通方式很受歡迎，例如地鐵？這個問題探討了公共交通方式，尤其是地鐵等大眾交通工具為何受到廣泛歡迎。回答時，可以從便捷性、經濟性、環保性等多個角度分析，舉例說明這些交通方式如何滿足現代城市居民的出行需求。