In pics: swans at Hekou Reservoir wetland in Yulin, NW China (9)

Swans are seen at the Hekou Reservoir wetland in Yulin, northwest China's Shaanxi Province, Oct. 31, 2021. To the south of the Maowusu Desert, the Yuyang District has witnessed improvement in eco-environment thanks to decades of afforestation efforts. (Xinhua/Tao Ming)