Workers cheer as they succeed in drilling a tunnel through the Dadu Mountain in Guanling Buyi and Miao Autonomous County, southwest China's Guizhou Province, Oct. 15, 2015. Stretching through the complicated karst terrain, the 11.82-kilometre tunnel, a part of the new high-speed railway connecting Shanghai and southwest China's Kunming, was drilled through on Thursday after five years' construction. (Xinhua/Liu Xu)
