Metropolitan region is different from a general cityregion and individual city, has its own characteristics and disciplinarians of forming and evolvement.
都市圈不同于一般的城市地区，也不同于一个个单体城市，而是有着自身的特点和形成与演化规律。
2
This paper argues that a second-tier city in a global cityregion not only plays important functions in the global urban system but also within the global cityregion.
作为国际城市区域中的二级城市不仅在全球城市体系中发挥作用，同时也在国际城市区域中担任重要的功能。
3
An urban area is the region surrounding and including a city.