In pics: Ban Somsanook No.2 Tunnel of China-Laos railway project

Photo taken on Dec. 13, 2017 shows Ban Somsanook No.2 Tunnel in Vientiane province, Laos. Ban Somsanook No.2 Tunnel holing-through on Tuesday became the first holing-through tunnel of the China-Laos railway project. (Xinhua/Liu Ailun)