Aerial photo shows the construction site of the south main tower of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)

Aerial photo shows the south main tower of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)

Aerial photo shows the south main tower (left) of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)

Workers pour concrete on the top of the south main tower of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)

Aerial photo shows the construction site of the south main tower of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)

Aerial photo shows builders working on the top of the south main tower of Quanzhou Bay cross-sea bridge of the Fuzhou-Xiamen high-speed railway in southeast China's Fujian Province, Sept. 15, 2020. The main structure of the south main tower of Quanzhou Bay cross-sea bridge has been completed on Tuesday. The 20-km-long bridge is a part of the Fuzhou-Xiamen high-speed railway that is designed to come on stream in 2022. (Xinhua/Lin Shanchuan)