精选优质文档-倾情为你奉上空气污染 英国需要采取更多措施来净化污浊的空气 Air pollution空气污染The big smoke雾都Britain needs to do more to clean up its dirty air 英国需要采取更多措施来净化污浊的空气VISITING Oxford Street, a road teeming with tatty shops and overcrowded with people, is plainly a trial. Less plainly, levels of nitrogen dioxide (NO2), a noxious gas, have been found to be around three times higher there than the legal limit. In 2013 the annual mean concentration of NO2 on the street was one of the highest levels found anywhere in