To displayvisibility on the class diagram, you place the visibility mark in front of the attribute's or operation's name.
为了在类图上的显示可见性，放置可见性标志于属性或操作的名字之前。
2
In other words, it's best to set a layer's visibility to display only the layers you want to.
换言之，只显示你想要看见的图层。
3
Warning display: autonomous, Zhangjiajie, Changde, Yiyang, Huaihua, Loudi and parts of the northern areas of dense fog will last 2-3 hours, low visibility, please pay attention to prevention.