地图符号库系统不仅是地理信息系统中不可缺少的基础功能模块之一，也是GIS的一个重要研究课题。
The Map Symbol Base System is not only one of the basic functions of Geographic Information System, but also an important research issue in GIS.
地图符号库系统是电子地图系统中不可缺少的功能模块之一。
The Map Symbol base System is one of the indispensable base functions in Electronic Map System.
标点符号是现代书面语中不可缺少的衔接和连贯标志。
Punctuation marks are an integrant sign of cohesion and coherence in modern writing.
应用推荐