Aerial photo taken on June 20, 2020 shows the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021. (Photos: Xinhua/Zhu Xiang)

Workers are busy at the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province, June 20, 2020. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

Workers are busy at the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province, June 20, 2020. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

A worker is busy at the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province, June 20, 2020. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

Aerial photo taken on June 20, 2020 shows the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

Photo taken on June 20, 2020 shows the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

Workers are busy at the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province, June 20, 2020. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.

Workers are busy at the construction site of the Yellow River bridge in Mengzhou, central China's Henan Province, June 20, 2020. The construction work of the Yellow River bridge on the No. 207 National Highway is under way. With its main bridge reaching 3,007 meters long and a designed speed of 80 km per hour, the bridge is expected to be completed by 2021.