High-speed railway starts operation in China's coldest region

A bullet train runs in the suburbs of Mudanjiang, northeast China's Heilongjiang Province on Dec. 25, 2015. A high-speed railway line officially went into operation on Tuesday, linking cities of Harbin and Mudanjiang in China's northernmost province of Heilongjiang, where the temperatures dip as low as minus 40 degrees Celsius. (Xinhua/Zhang Chunxiang)