Train attendants take a selfie to mark the full operation of Shanghai-Kunming high-speed rail in Kunming, Southwest China's Yunnan province, on Dec 28, 2017.The 2,264-kilometer line, stretching from the coastal city of Shanghai in the east, to Kunming, capital of Southwest China's Yunnan province, boasts the longest high-speed track in the country. [Photo by Zou Hong/chinadaily.com.cn]