Boats drive on the water of the Three Gorges in Zigui County in central China's Hubei Province, April 21, 2018. (Photo by Zheng Jiayu/Xinhua)

Photo taken on July 2, 2019 shows a dirty-water processing factory in Jiaocheng County, north China's Shanxi Province. (Xinhua/Yang Chenguang)

Villagers walk in paddy fields in Youyang Tujia and Miao Autonomous County in southwest China's Chongqing, May 15, 2020. (Photo by Chen Bisheng/Xinhua)

Swans fly over the Swan Lake National Urban Wetland Park in Sanmenxia, central China's Henan Province, Nov. 14, 2019. (Xinhua/Hao Yuan)

Aerial photo taken on Aug. 25, 2019 shows the Mergel Gol River in Hulun Buir, north China's Inner Mongolia Autonomous Region. (Xinhua/Shen Bohan)

Aerial photo taken on July 26, 2019 shows a forest park in Qinling Mountains in Xi'an, northwest China's Shaanxi Province. (Xinhua/Liu Xiao)

Aerial photo taken on Aug. 2, 2017 shows the Red Beach scenic area in Panjin, northeast China's Liaoning Province. (Xinhua)

Aerial photo taken on Oct. 31, 2018 shows the scenery of Xiezi Mountain in Jinan, capital city of east China's Shandong Province. (Xinhua/Zhu Zheng)

A sanitory worker checks garbage at a community in Hongkou District of Shanghai, east China, June 24, 2019. (Xinhua/Fang Zhe)

Aerial photo taken on Sept. 4, 2020 shows the scenery of a lake in Jianfengling nature reserve at Hainan Tropical Rainforest National Park in south China's Hainan Province. (Xinhua/Pu Xiaoxu)

Photo taken on Sept. 17, 2020 shows a view of downtown Beijing, capital of China. (Xinhua/Wang Jianhua)

A tramcar runs past begonia flowers in Suzhou, east China's Jiangsu Province, March 28, 2018. (Photo by Xu Zhiqiang/Xinhua)