Citizens exercise near the renovated city wall in Yanchi County, northwest China's Ningxia Hui Autonomous Region, May 28, 2019. Located on the southern edge of the Maowusu Desert, Yanchi County was once poverty-stricken and suffered from desertification. But after years of efforts, the environment there has been restored, and the county has also shaken off poverty. (Xinhua/Wang Peng)