Passengers Zheng Xiang (1st R) and Tan Zhuoyi (2nd R) sits on a subway train of Subway Line 10 to leave the Shuangliu International Airport in Chengdu, capital of southwest China's Sichuan Province, Sept. 6, 2017. The first phase project of Chengdu's Subway Line 10 started its trial operation on Wednesday. (Xinhua/Jiang Hongjing)
