合并与修改地图
用 Show 合并地图并修改其选项.
取两个地图，每个都包含一个彩色多边形.
In[1]:=
spain = GeoGraphics[{GeoStyling[Red, Opacity[0.5]],
Polygon[Entity["Country", "Spain"]]}]Out[1]=
In[2]:=
italy = GeoGraphics[{GeoStyling[Green, Opacity[0.5]],
Polygon[Entity["Country", "Italy"]]}]Out[2]=
合并地图然后做些修，这里是加入了地理网格线.
In[3]:=
Show[spain, italy, GeoGridLines -> Automatic]Out[3]=
进一步修改地图，现在来改变地理背景的样式.
In[4]:=
Show[spain, italy, GeoGridLines -> Automatic];
Show[%, GeoBackground -> "Satellite"]Out[4]=
