Every Saturday morning, at 9 a.m., more than 50,000 runners set off to run 5 km around their local park. The Parkrun phenomenon began with a dozen friends and has inspired 400 events in the UK and more abroad. Events are free, staffed by thousands of volunteers. Runners range from four years old to grandparents; their times range from Andrew Baddeley’s world record 13 minutes 48 seconds up to an hour.

    Parkrun is succeeding where London’s Olympic “legacy” is failing. Ten years ago on Monday, it was announced that the Games of the 30th Olympiad would be in London. Planning documents pledged that the great legacy of the Games would be to lever a nation of sport lovers away from their couches. The population would be fitter, healthier and produce more winners. It has not happened. The number of adults doing weekly sport did rise, by nearly 2 million in the run-up to 2012—but the general population was growing faster. Worse, the numbers are now falling at an accelerating rate. The opposition claims primary school pupils doing at least two hours of sport a week have nearly halved. Obesity has risen among adults and children. Official retrospections continue as to why London 2012 failed to “inspire a generation”. The success of Parkrun offers answers.

    Parkun is not a race but a time trial: your only competitor is the clock. The ethos welcomes anybody. There is as much joy over a puffed-out first-timer being clapped over the line as there is about top talent shining. The Olympic bidders, by contrast, wanted to get more people doing sports and to produce more elite athletes. The dual aim was mixed up: The stress on success over taking part was intimidating for newcomers.

    Indeed, there is something a little absurd in the state getting involved in the planning of such a fundamentally “grassroots” concept as community sports associations. If there is a role for government, it should really be getting involved in providing common goods—making sure there is space for playing fields and the money to pave tennis and netball courts, and encouraging the provision of all these activities in schools. But successive governments have presided over selling green spaces, squeezing money from local authorities and declining attention on sport in education. Instead of wordy, worthy strategies, future governments need to do more to provide the conditions for sport to thrive. Or at least not make them worse.

答案精析：根据题干中的London’s Olympic “legacy” 和failed可定位至第二段第一句。该段第四句指出了伦敦奥运会的期望是国民可以健康（fitter, healthier），随后紧接着说到这一期望并没有发生。随后指出成人和小学生的运动参与人数和时间均有下降。该段末尾也提到肥胖率上升（obesity has risen）。由此可见，伦敦奥运会没有达到人们的期望，未能有效促进民众参加体育运动，因此选择B项。

错项排除：文章第二段提到the general population was growing faster，“人口增长”是自然规律，并非是未能实现的目标，因此排除A项。原文中并未提及提升城市形象的内容，因此排除C项。第二段倒数第四句提到“每周进行两小时体育锻炼的小学生的数量几乎减半”，由此可知，伦敦奥运会“遗留影响”未能增加校内体育锻炼的时间，因此D项错误。