Passengers take the train on the Line S1 in Beijing, capital of China, Dec. 30, 2017. The 10.2-km Line S1 is Beijing's first medium-low speed maglev line. It connects the western suburban districts of Mentougou and Shijingshan. 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/Hou Jiqing)