Photo taken on June 6, 2017 shows a bridge under construction for Beijing's maglev line S1 across Yongding River in Beijing, capital of China. Beijing's first medium-low speed maglev Line S1, which connects the city's western district of Mentougou to the Pingguoyuan subway station in Shijingshan district, is expected to open this year. (Xinhua/Xing Guangli)