ThecapitalcityofSouthKorea,Seoul,isputtingup300newstree...
問題詳情：ThecapitalcityofSouthKorea,Seoul,isputtingup300newstreetsingswiththepurposeof___41___(warn)pedestriansaboutthedangersofwalkingwhileabsorbedintheirsmartphones.Thefirstsignshavebeenatfivelocatio...