Yesterday morning, a pair of black swans was seen frolicking and dancing on the West Lake, attracting numerous tourists to halt and watch them. 

Black swans are demanding for water quality and only stay in clean water environment. The emergence of black swans on the West Lake indicates the improved ecological environment of the West Lake.

Black swans dabbling in the West Lake is not only a beautiful sight of the city, but also indicates a sound environment of the city.