Aerial photo taken on Oct. 7, 2019 shows a view of the Lhasa River valley in Lhasa, southwest China's Tibet Autonomous Region. (Photo by Sun Fei/Xinhua)

Aerial photo taken on Oct. 7, 2019 shows a view of the Lhasa River valley in Lhasa, southwest China's Tibet Autonomous Region. (Photo by Sun Fei/Xinhua)

Aerial photo taken on Oct. 7, 2019 shows a view of the Lhasa River valley in Lhasa, southwest China's Tibet Autonomous Region. (Photo by Sun Fei/Xinhua)

Aerial photo taken on Oct. 7, 2019 shows a view of the Lhasa River valley in Lhasa, southwest China's Tibet Autonomous Region. (Photo by Sun Fei/Xinhua)

Aerial photo taken on Oct. 7, 2019 shows a view of the Lhasa River valley in Lhasa, southwest China's Tibet Autonomous Region. (Photo by Sun Fei/Xinhua)