Trucks undergo a load test on the 1,720 meters Yunwu Bridge of Duyun-Anshun Expressway in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)

Trucks undergo a load test on the deck of Yunwu Bridge in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)

Trucks undergo a load test on the deck of Yunwu Bridge in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)

Trucks undergo a load test on the deck of Yunwu Bridge in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)

A driver drives a truck to attend a load test on the deck of Yunwu Bridge in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)

Trucks undergo a load test on the deck of Yunwu Bridge in Yunwu Town, Guiding County, Qiannan Prefecture, Guizhou Province, June 8, 2021. (Photo/Qu Honglun)