A passenger buys ticket at the Futian underground railway station in Shenzhen, south China's Guangdong Province, Dec. 30, 2015. Asia's largest underground railway station opened on Wednesday in the southern Chinese city of Shenzhen, launching high-speed rail service between Guangzhou and Hong Kong.The new line slashes travel time between Guangzhou and Hong Kong to half an hour. (Xinhua/Lu Hanxin)