昨天的东西又看了遍，发现老师在最后有一个总结性的一段很有价值，整理如下：
L3.1:
In this lesson we learned how to explore brand new data using the identify tool by looking at the attribute table and selecting features and by using the find tool. We also looked at the metadata in order to figure out what the data means and then we also added a raster data set and explored it in the context of our base map imagery.
identify tool：注释
attribute table：一个要素的特质的集合
find tool：用于找到有同一特质的要素
metadata：叙述性文件
raster data set：基础数据包，可以帮助分析数据
L3.2:
In this lecture, we learned about the layer properties pane. We learned how to set categorical symbology and just standard symbology. You also learned how to label features, and then you learned how to set scale dependent rendering and define a definition query to limit what's displayed on your map.
layer properties pane：层的特制显示的设定
categorical symbology：地图的分块
set scale dependent rendering：比例尺设置显示的多少
definition query：在设定中的definition选项里面，依据一定的需求，设置需要显示的要素
label features：在某些要素上显示一些信息
