anchor.diff:      Without a barrel, a consumer needs three import statements:
       
       如果没有封装桶，消费者需要三条导入语句：  
  +    
     code-example.
       import { HeroComponent } from '../heroes/hero.component.ts';
       import { Hero }          from '../heroes/hero.model.ts';
  
positive.code:     Data values flow *into* this property from the data source identified
      in the template expression to the right of the equal sign.
  
      输入属性是一个指令属性，可以作为[属性绑定 (property binding)](./template-syntax.html#property-binding)的目标。
      数据值会从模板表达式等号右侧的数据源流入这个属性。
  
      See the [Input and output properties](./template-syntax.html#inputs-outputs) section of the [Template Syntax](./template-syntax.html) page.
  
negative.code:     A mechanism for encapsulating and intercepting
      a JavaScript application's asynchronous activity.
  
      区域是一种用来封装和截听 JavaScript 应用程序异步活动的机制。
      
      The browser DOM and JavaScript have a limited number
        of asynchronous activities,  such as DOM events (for example, clicks),
        [promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise), and
        [XHR](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest)
        calls to remote servers.
  
      浏览器中的 DOM 和 JavaScript 之间常会有一些数量有限的异步活动，
        例如 DOM 事件（例如点击）、[承诺 (promise)](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)
        和通过 [XHR](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) 调用远程服务。
        
      Zones intercept all of these activities and give a "zone client" the opportunity
        to take action before and after the async activity finishes.
  
      区域能截听所有这些活动，并让“区域的客户”有机会在异步活动完成之前和之后采取行动。
      
      Angular runs your application in a zone where it can respond to
        asynchronous events by checking for data changes and updating
        the information it displays via [data bindings](#data-binding).
  
      Angular 会在一个 Zone 区域中运行应用程序，在这个区域中，它可以对异步事件做出反应，可以通过检查数据变更、利用[数据绑定 (data bindings)](#data-binding) 来更新信息显示。
      
      Learn more about zones in this
        [Brian Ford video](https://www.youtube.com/watch?v=3IqtmUscE_U).
  
      更多信息，见 [Brian Ford 的视频](https://www.youtube.com/watch?v=3IqtmUscE_U)。
  