ArcGIS练习数据，包括北美（美国和加拿大）的主要城市、城市区域、公路网、铁路网、机场、地铁、湖泊等数据！
North_America_Airports.lpk
North_America_Cities.lpk
North_America_City_Areas.lpk
North_America_Highways.lpk
North_America_Institutions.lpk
North_America_Major_Lakes.lpk
North_America_Major_Roads.lpk
North_America_Railroads.lpk
North_America_Streetscarto.lpk
