Children show greeting cards made to mark the World Hello Day which falls on Nov. 21 annually at a kindergarten at Taihe County, east China's Jiangxi Province. (Xinhua/Deng Heping)
Children show greeting cards made to mark the World Hello Day which falls on Nov. 21 annually at a center primary school at Yangguantun Township of Chiping County, east China's Shandong Province. (Xinhua/Zhao Yuguo)
Children show greeting cards made to mark the World Hello Day which falls on Nov. 21 annually at a kindergarten at Qingzhou City, east China's Shandong Province. (Xinhua/Wang Jilin)
Children show greeting cards made to mark the World Hello Day which falls on Nov. 21 annually at the experimental primary school at Baokang County, central China's Hubei Province. (Xinhua/Yang Tao)