（单词翻译:单击）
Beijing is home to an extensive 17-line subway system. But although the system is the biggest it has ever been, in many people's eyes, it is still not big enough.
During the first half of 2014, nearly 8.5 million people took the subway every day. The entire population of Beijing is just over 22 million, which means almost one third of the city's population is on the move, relying on the transportation network to get them where they need, or want, to be.
More than 9.8 million people rode Beijing’s subway on July 11, during the peak of the summer’s tourism boom1. And some people are blaming the relatively2 low subway fares for huge crowds.
