Tourists walk along the Swan Lake in Hefei, east China's Anhui Province, April 5, 2019. (Xinhua/Zhang Duan)

Aerial photo taken on April 5, 2019 shows tourists flying kites by the Swan Lake in Hefei, east China's Anhui Province. (Xinhua/Zhang Duan)

Aerial photo taken on April 5, 2019 shows tourists near the Swan Lake in Hefei, east China's Anhui Province. (Xinhua/Zhang Duan)