This pane shows all the projects you have under the same workspace and their objects in a hierarchical structure.

该面板以层次结构显示同一个工作区中的所有项目，以及它们的对象。

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A tree is a hierarchical structure that defines a parent-child relationship.

树是一个定义了“父子”关系的层次结构。

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Certain features can also use this field to help generate a hierarchical structure of the organization.

某些特性还能使用该字段来帮助生成公司的层次结构。

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Likewise, the bill proposes a more hierarchical structure for prosecutors.

ECONOMIST: A change, they say, is as good as a rest

Evangelical Protestant churches, which have a less hierarchical structure and appeal more directly to poor people, have been making great inroads not only in Argentina but in many other countries in the region.

BBC: New Pope seeks to heal divisions in Latin America

So, to cut to the logical chase, what you have is a many-to-many mapping with a hierarchical (family tree) structure.

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