along Beijing and Tianjin

• 环京津

along Beijing and Tianjin的用法和样例：

例句

1. Beijing will work closely with relevant provinces in the ecological improvement program for Beijing, Tianjin, and the surrounding area organized by the central goverment.
   积极参与环京津地区防沙治沙工程和国家有关首都生态圈建设工作。