Photo taken on Sep 29, 2022 shows the construction site of an undersea tunnel in Dalian Bay, northeast China's Liaoning Province. Construction of an undersea tunnel was completed on Thursday in Dalian Bay, which accommodates a two-way six-lane urban expressway through the sea area in the city of Dalian, Liaoning Province. Photo:Xinhua

Photo taken on Sep 29, 2022 shows the site of the final joint in an undersea tunnel in Dalian Bay, northeast China's Liaoning Province. Photo:Xinhua

Workers work at the construction site of an undersea tunnel in Dalian Bay, northeast China's Liaoning Province, Sep 29, 2022. Photo:Xinhua

Workers work at the construction site of an undersea tunnel in Dalian Bay, northeast China's Liaoning Province, Sep 29, 2022. Photo:Xinhua

A worker works at the construction site of an undersea tunnel in Dalian Bay, northeast China's Liaoning Province, Sep 29, 2022. Photo:Xinhua

A worker works at the construction site of an undersea tunnel in Dalian Bay, northeast China's Liaoning Province, Sep 29, 2022. Photo:Xinhua