The Blue Sky rescue team, formed by local volunteers, often pick garbage during their practice at the scenic area, calling on tourists here to protect the environment. (Photos: Xinhua)

Aerial photo taken on Oct. 21, 2020 shows members of Zhangjiajie Blue Sky rescue team picking garbage while practicing cable descent at Huangshizhai scenic spot in Zhangjiajie, central China's Hunan Province.

A member of Zhangjiajie Blue Sky rescue team introduces knowledge of environmental protection to tourists at Huangshizhai scenic spot in Zhangjiajie, central China's Hunan Province, Oct. 21, 2020.

Members of Zhangjiajie Blue Sky rescue team practice cable descent at Huangshizhai scenic spot in Zhangjiajie, central China's Hunan Province, Oct. 21, 2020.

Photo taken on Oct. 21, 2020 shows members of Zhangjiajie Blue Sky rescue team picking garbage while practicing cable descent at Huangshizhai scenic spot in Zhangjiajie, central China's Hunan Province.