Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Purbu Zhaxi)

Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Li Xin)

Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Purbu Zhaxi)

Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Li Xin)

Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Purbu Zhaxi)

Aerial photo taken on Oct. 28, 2019 shows the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Li Xin)

A car runs on the Duobu bridge in Nyingchi, southwest China`s Tibet Autonomous Region, Oct. 28, 2019. The Duobu bridge is located on the Lhasa-Nyingchi high-grade road. (Xinhua/Purbu Zhaxi)