anchor.diff:      where we also explain why *target* properties require this special treatment and 
       *source* properties do not.
       
  -    我们在[这里](../guide/attribute-directives.html#why-input)详细解释了输入属性，以及为什么*目标属性*需要“显式定义”这样的特殊待遇，而*来源属性*却不需要。
  +    我们在[这里](../guide/attribute-directives.html#why-input)详细解释了输入属性，以及为什么*目标属性*需要“显式定义”这样的特殊待遇，而*源属性*却不需要。
       
   :marked
     There are a couple of ways we can declare that `hero` is an *input*. 
  
positive.code: :marked
    ## Refresh the AppModule
    
    ## 刷新AppModule
    
    We return to the `AppModule`, the application's root module, and teach it to use the `HeroDetailComponent`.
  
  
negative.code:     
      We like to identify at a glance which classes are components and which files contain components. 
      
      我们希望一眼就能看出哪些类是组件，以及哪些文件包含组件。
      
      Notice that  we have an `AppComponent` in a file named `app.component.ts` and our new
      `HeroDetailComponent` is in a file named `hero-detail.component.ts`. 
  