Wang Mutou (1st, L) interprets at Baiyangdian memorial hall of anti-Japanese war in Xiongan New Area, north China's Hebei Province, April 10, 2019. Restoration work has started in Baiyangdian Lake, northern China's largest freshwater body. High-pollution and energy-intensive production has been tackled. As a result, water quality has improved remarkably. [Photo/Xinhua]