Undersea tunnel of HK-Zhuhai-Macao Bridge to be joined together

Photo taken on April 28, 2017 shows the west artificial island as part of the Hong Kong-Zhuhai-Macao Bridge in Zhuhai, south China's Guangdong Province. Part of the project, the 5,664-meter-long undersea tunnel is to be joined together on May 2, 2017. [Photo: Xinhua/Liu Dawei]

Photo taken on April 28, 2017 shows the breakwater of the west artificial island as part of the Hong Kong-Zhuhai-Macao Bridge in Zhuhai, south China's Guangdong Province. Part of the project, the 5,664-meter-long undersea tunnel is to be joined together on May 2, 2017. [Photo: Xinhua/Liu Dawei]

Photo taken on April 28, 2017 shows the entrance of the tunnel under construction, as part of the Hong Kong-Zhuhai-Macao Bridge in Zhuhai, south China's Guangdong Province. Part of the project, the 5,664-meter-long undersea tunnel is to be joined together on May 2, 2017. [Photo: Xinhua/Liu Dawei]

Photo taken on April 28, 2017 shows as part of the Hong Kong-Zhuhai-Macao Bridge in Zhuhai, south China's Guangdong Province. Part of the project, the 5,664-meter-long undersea tunnel is to be joined together on May 2, 2017. [Photo: Xinhua/Liu Dawei]

Photo taken on April 28, 2017 shows as part of the Hong Kong-Zhuhai-Macao Bridge in Zhuhai, south China's Guangdong Province. Part of the project, the 5,664-meter-long undersea tunnel is to be joined together on May 2, 2017. [Photo: Xinhua/Liu Dawei]