Workers lay railway tracks at the construction site of Chengdu-Guiyang railway line in Yibin City, southwest China's Sichuan Province, May 30, 2018. The track laying of Sichuan section of Chengdu-Guiyang railway line was completed on Wednesday. (Xinhua/Xue Yubin)

Workers lay railway tracks at the construction site of Chengdu-Guiyang railway line in Yibin City, southwest China's Sichuan Province, May 30, 2018. The track laying of Sichuan section of Chengdu-Guiyang railway line was completed on Wednesday. (Xinhua/Xue Yubin)

Workers lay railway tracks at the construction site of Chengdu-Guiyang railway line in Yibin City, southwest China's Sichuan Province, May 30, 2018. The track laying of Sichuan section of Chengdu-Guiyang railway line was completed on Wednesday. (Xinhua/Xue Yubin)

Workers lay railway tracks at the construction site of Chengdu-Guiyang railway line in Yibin City, southwest China's Sichuan Province, May 30, 2018. The track laying of Sichuan section of Chengdu-Guiyang railway line was completed on Wednesday. (Xinhua/Xue Yubin)

Workers lay railway tracks at the construction site of Chengdu-Guiyang railway line in Yibin City, southwest China's Sichuan Province, May 30, 2018. The track laying of Sichuan section of Chengdu-Guiyang railway line was completed on Wednesday. (Xinhua/Xue Yubin)