A train arrives at Xingcheng station on the Yanfang Line in Beijing, capital of China, Dec. 30, 2017. Yanfang Line is China's first fully domestically-developed automated subway. It has nine stations on its 14.4-km main line, linking the areas of Yanshan and Fangshan. Three more subway lines, which are Yanfang Line, Line S1 and West Suburb Line, started operation in Beijing Saturday, bringing the total length of metros in the Chinese capital to 608 kilometers. (Xinhua/Liu Xianguo)