Photo taken on Nov. 26, 2015 shows Shanghai Railway Station starting to sell group tickets for "chunyun", in Shanghai, east China. China Railway Corporation (CRC), operator of China's rail network, started to sell train tickets on the Internet, the mobile app and through the phone, for the 40-day travel period known as "chunyun" on Thursday. "Chunyun", sometimes called the world's largest human migration, is the hectic travel period surrounding Chinese New Year. This year, chunyun will begin on Jan. 24 and last until March 3. (Photo: Xinhua/Chen Fei)
