![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)](http://www.ecns.cn/hd/2018/11/21/ffcd912cb93745039e98a58ec1584638.jpg)
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)](http://www.ecns.cn/hd/2018/11/21/d1d5ae81adc7482a83f6ec95909a074d.jpg)
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)](http://www.ecns.cn/hd/2018/11/21/b08c638eb1f046178c3b1ba041861d01.jpg)
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)](http://www.ecns.cn/hd/2018/11/21/1ea77dae3c3c46fb9eff2630165f5242.jpg)
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)