anchor.diff:      :marked
         Read more about the `[class]` binding in the [Template Syntax](../guide/template-syntax.html#ngClass "Template syntax: NgClass") guide.
   
  -      关于属性绑定的更多信息，见[模板语法](../guide/template-syntax.html#property-binding)。
  +      关于`[class]`绑定的更多信息，参见[模板语法](../guide/template-syntax.html#ngClass "Template syntax: NgClass")。
   
     :marked
       The final version of the `<li>` looks like this:
  +    
     +makeExample('toh-2/ts/src/app/app.component.1.html', 'class-selected-2', 'app.component.ts (styling each hero)')(format=".")
   
     :marked
  
positive.code:     所以我们要把`hero`属性**替换**成`selectedHero`属性。
  
    +makeExample('toh-2/ts/src/app/app.component.ts', 'selected-hero', 'src/app/app.component.ts (selectedHero)')
    :marked
      The hero names should all be unselected before the user picks a hero, so
      you won't initialize the `selectedHero` as you did with `hero`.
  
negative.code:     :marked
        Don't forget the asterisk (`*`) in front of `ngIf`.
        
        别忘了`ngIf`前的星号 (`*`)。
  
    :marked
      The app no longer fails and the list of names displays again in the browser.
  