Manycitieshavesubwaysandundergroundpublictransportation...
问题详情：Manycitieshavesubwaysandundergroundpublictransportationtotakelocalsandtouristsalikerapidlyaroundthecity．However,there’ssomethingdifferentaboutridingaLondonsubway．Itmaynotlookdifferent,butthehis...