Left-behind children, whose parents go to other places to work, do their homework at an after-school care center in Danying Community of Yanji City, Yanbian Korean Autonomous Prefecture in northeast China's Jilin Province, May 22, 2013. More than 30,000 children are left behind by their parents who choose to go to South Korea to work in the Yanbian Korean Autonomous Prefecture. The local government established 20 after-school care centers to provide these left-behind children with the after-class care. [Photo/Xinhua]