
Children play a drama of garbage classification theme during an activity to celebrate the International Children's Day at Xixi branch of Zhejiang University Preschool in Hangzhou, east China's Zhejiang Province, June 1, 2017. (Xinhua/Xu Yu)

Children play a drama of garbage classification theme during an activity to celebrate the International Children's Day at Xixi branch of Zhejiang University Preschool in Hangzhou, east China's Zhejiang Province, June 1, 2017. (Xinhua/Xu Yu)