China-Laos railway's longest tunnel holed

Photo taken on Dec. 27, 2019 shows the Ban Sen No. 2 Tunnel, south to the ancient Lao capital of Luang Prabang, some 170 km north of capital Vientiane. China-Laos railway tunnels' construction has made a decisive breakthrough, with its longest tunnel drilled through on Friday morning in the tropical mountains of northern Laos. (Photo by Kaikeo Saiyasane/Xinhua)