The base package including point class, line class, area class, volume class, complex object class and relation class, is the base of the application package and the combination package.

其中基础类包是应用类包和组合类包的基础，它用点、线、面、体、复杂对象和关系类等基本的要素表示三维空间。

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The base package including point class, line class, area class, volume class, complex object class and relation class, is the base of the application package and the combination package.

其中基础类包是应用类包和组合类包的基础，它用点、线、面、体、复杂对象和关系类等基本的要素表示三维空间。

youdao