Manycitieshavesubwaysandundergroundpublictransportation...
問題詳情：Manycitieshavesubwaysandundergroundpublictransportationtotakelocalsandtouristsalikerapidlyaroundthecity．However,there’ssomethingdifferentaboutridingaLondonsubway．Itmaynotlookdifferent,butthehis...