A tourist takes selfies beside the first high-speed train from northwest China's Xi'an to southwest China's Chengdu at the Xi'an North Railway Station in Xi'an, capital of Shaanxi Province, Dec. 6. 2017. High-speed rail line linking Xi'an and Chengdu, capital of Sichuan Province, went into operation Wednesday, slashing the travel time between the two cities from about 11 hours to just 4. [Photo/Xinhua]