anchor.diff:  :marked
     We're finished with the application routes.
   
  -  我们已经做好了该应用的路由。
  +  我们已经完成了该应用的路由。
   
   
     We won't add a `'Hero Detail'` link to the template because users
  
positive.code:   We need `OnInit` interface because we'll initialize the heroes in the `ngOnInit` method as we've done before.
    We need the `Hero` and `HeroService` symbols in order to reference those types.
  
    我们得实现`OnInit`接口，因为我们要在`ngOnInit`方法中初始化英雄数组 —— 就像上次一样。
    我们需要导入`Hero`类和`HeroService`类来引用它们的数据类型。
  
    Now implement the `DashboardComponent` class like this:
  
negative.code:   
    * Pull the routes into a variable. You might export it in future and it clarifies the _Routing Module_ pattern.
  
    * 将路由抽出到一个变量中。你将来可能会导出它。而且它让**路由模块**模式更加明确。
  
    * Add `RouterModule.forRoot(routes)` to `imports`.
  
  