In this file photo released on May 25, 1963, children of Yanji Municipal Nursery rehearse for an upcoming song and dance gala in Yanji of Yanbian Korean Autonomous Prefecture, northeast China's Jilin Province. 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/Liu Entai)