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     ## The Injector Tree
  +
     ## 注入器树
   
     In the [Dependency Injection](./dependency-injection.html) chapter
  
positive.code:   We learned the basics of Angular Dependency injection in the
    [Dependency Injection](./dependency-injection.html) chapter.
    
    在[依赖注入](./dependency-injection.html)一章中，我们已经学过了Angular依赖注入的基础知识。
  
    Angular has a Hierarchical Dependency Injection system.
    There is actually a tree of injectors
  
negative.code:   We oversimplified. In fact, there is no such thing as ***the*** injector!
    An application may have multiple injectors!
    
    我们其实有点简化过度了。实际上，没有***那个（唯一的）***注入器这回事，一个应用中可能有多个注入器。
  
    An Angular application is a tree of components. Each component instance has its own injector!
    The tree of components parallels the tree of injectors.
    
    一个 Angular 应用是一个组件树。每个组件实例都有自己的注入器！
    组件的树与注入器的树平行。
  
  
  