In this file photo released on April 4, 1960, Li Changlan (1st R), a kindergarten teacher, measures children's heights at Xinjiekou Guozishi Kindergarten in Beijing, capital of China. China celebrated International Children's Day on June 1, 2019. These file photos recorded how Chinese children spent their childhood in nurseries and kindergartens dozens of years ago. (Xinhua/Yang Zhanhua)