Photo taken on April 6, 2020 shows the under-construction bridge across the Yarlung Zangbo River on the Lhasa-Nyingchi Railway in Jiacha County of Shannan City, southwest China's Tibet Autonomous Region. The construction team completed the closure of the main girder of the 525.1-meter bridge on June 20, 2020. (Xinhua/Chogo)

Workers rest during a break at the under-construction bridge across the Yarlung Zangbo River on the Lhasa-Nyingchi Railway in Jiacha County of Shannan City, southwest China's Tibet Autonomous Region, June 19, 2020. The construction team completed the closure of the main girder of the 525.1-meter bridge on Saturday. (Xinhua/Chogo)

Photo taken on June 19, 2020 shows part of the under-construction bridge across the Yarlung Zangbo River on the Lhasa-Nyingchi Railway in Jiacha County of Shannan City, southwest China's Tibet Autonomous Region. The construction team completed the closure of the main girder of the 525.1-meter bridge on Saturday. (Xinhua/Chogo)

Laborers work at the under-construction bridge across the Yarlung Zangbo River on the Lhasa-Nyingchi Railway in Jiacha County of Shannan City, southwest China's Tibet Autonomous Region, June 20, 2020. The construction team completed the closure of the main girder of the 525.1-meter bridge on Saturday. (Xinhua/Chogo)

Photo taken on June 20, 2020 shows the under-construction bridge across the Yarlung Zangbo River on the Lhasa-Nyingchi Railway in Jiacha County of Shannan City, southwest China's Tibet Autonomous Region. The construction team completed the closure of the main girder of the 525.1-meter bridge on Saturday. (Xinhua/Chogo)