anchor.diff:  :marked
     Our goal is to move the detail to its own view and navigate to it when the user decides to edit a selected hero.
   
  -  我们要做的是将详情建移动到它自己的视图，并在用户决定编辑一个英雄时导航到它。
  +  我们要做的是将英雄详情移动到它自己的视图，并在用户决定编辑一个英雄时导航到它。
   
     Delete the `<h1>` at the top (we forgot about it during the `AppComponent`-to-`HeroesComponent` conversion).
     
  -  删除顶部的`<h1>`（在从`AppComponent`转到`HeroesComponent`时忘记改它了）。
  +  删除顶部的`<h1>`（在从`AppComponent`转到`HeroesComponent`时忘记修改它了）。
     
     Delete the last line of the template with the `<my-hero-detail>` tags.
   
  
positive.code:     extract the `id` parameter value from the `ActivatedRoute` service
      and use the `HeroService` to fetch the hero with that `id`.
  
      在`ngOnInit`生命周期钩子中，使用可观察对象`params`从`ActivatedRoute`服务中提取`id`参数，并且使用`HeroService`来获取具有这个`id`的英雄数据。
  
  +makeExcerpt('app/hero-detail.component.ts', 'ngOnInit')
  
  
negative.code:   We don't really expect users to paste a route URL into the address bar.
    We add an anchor tag to the template which, when clicked, triggers navigation to the `HeroesComponent`.
  
    我们当然不会真让用户往地址栏中粘贴路由的URL，而应该在模板中的什么地方添加一个锚标签。点击时，就会导航到`HeroesComponent`组件。
  
    The revised template looks like this:
  
  