Aerial photo taken on Oct. 27, 2019 shows the Polonggou grand bridge in Bomi County, Nyingchi of southwest China's Tibet Autonomous Region. Polonggou grand bridge is the largest double pylon cable-stayed bridge in Tibet Autonomous Region. (Xinhua/Sun Fei)

Photo taken on Oct. 27, 2019 shows the Polonggou grand bridge in Bomi County, Nyingchi of southwest China's Tibet Autonomous Region. Polonggou grand bridge is the largest double pylon cable-stayed bridge in Tibet Autonomous Region. (Xinhua/Sun Fei)

Aerial photo taken on Oct. 27, 2019 shows the Polonggou grand bridge in Bomi County, Nyingchi of southwest China's Tibet Autonomous Region. Polonggou grand bridge is the largest double pylon cable-stayed bridge in Tibet Autonomous Region. (Xinhua/Sun Fei)

A car runs on the Polonggou grand bridge in Bomi County, Nyingchi of southwest China's Tibet Autonomous Region, Oct. 27, 2019. Polonggou grand bridge is the largest double pylon cable-stayed bridge in Tibet Autonomous Region. (Xinhua/Sun Fei)

Aerial photo taken on Oct. 27, 2019 shows the Polonggou grand bridge in Bomi County, Nyingchi of southwest China's Tibet Autonomous Region. Polonggou grand bridge is the largest double pylon cable-stayed bridge in Tibet Autonomous Region. (Xinhua/Sun Fei)