anchor.diff:      We bind the `RouterLink` directive (another of the `RouterModule` directives) to a string
       that tells the router where to navigate when the user clicks the link.
     
  -    注意，链接标签中的`[routerLink]`绑定。我们把`RouterLink`指令(`ROUTER_DIRECTIVES`中的另一个指令)绑定到一个字符串。它将告诉路由器，当用户点击这个链接时，应该导航到哪里。
  +    注意，锚标签中的`[routerLink]`绑定。我们把`RouterLink`指令(`ROUTER_DIRECTIVES`中的另一个指令)绑定到一个字符串。它将告诉路由器，当用户点击这个链接时，应该导航到哪里。
     
       Since our link is not dynamic, we define a *routing instruction* with a **one-time binding** to our route **path**.
       Looking back at the route configuration, we confirm that `'/heroes'` is the path of the route to the `HeroesComponent`.
  
positive.code: :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。
  
    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）。
    
    Delete the last line of the template with the `<my-hero-detail>` tags.
  
  
negative.code:   using the `Location` service we injected previously.
  
    现在用户可以点击`AppComponent`中的两个链接，或点击浏览器的“后退”按钮。
    我们来添加第三个选项：一个`goBack`方法，它使用之前注入的`Location`服务，利用浏览器的历史堆栈，导航到上一步。
  
  +makeExcerpt('app/hero-detail.component.ts', 'goBack')
  
  