anchor.diff:      Most applications need those capabilities and most applications
       should run in Internet Explorer.
   
  +    一开始，我们先进行IE的polyfill（译注：指填充，用js来弥补浏览器原本不具备的能力）。
  +    IE需要填充才能正确运行依赖ES2015 promise（译注：ES2015的新特性，用于支持异步代码）和动态模块加载特性的应用程序。
  +    大多数应用还是得运行在IE中，所以我们需要这些能力。
  +
       Next are the polyfills for Angular2, `angular2-polyfills.js`.
  +    
  +    下一个是Angular2的polyfill —— `angular2-polyfills.js`。
       
       Then the [SystemJS](#systemjs) library for module loading,
       followed by the Reactive Extensions RxJS library.
  +    
  +    下一个是响应式编程的扩展库RxJS。
  +    
  +    最后则是为实现模块加载功能而引入的[SystemJS](#systemjs)库。
  +
     .l-sub-section
       :marked
         Our QuickStart doesn't use the Reactive Extensions 
         but any substantial application will want them
         when working with observables.
         We added the library here in QuickStart so we don't forget later.
  +      
  +      我们的QuickStart不会用到响应式扩展，但是大量的应用需要它们来提供observable（译注：响应式编程的核心特性，指监听数据的变更以便做出响应）特性。
  +      我们把它加到QuickStart中，以免将来忘了。
  +
     :marked
       Finally, we loaded the web development version of Angular 2 itself.
  +    
  +    最后，我们加载Angular2的“Web开发版”。
   
       We'll make different choices as we gain experience and
       become more concerned about production qualities such as
       load times and memory footprint.
  +    
  +    一旦我们更有经验、对产品质量更加关注（如加载时间、内存脚印等），我们也可以做出不同的选择
   
     a(id="systemjs")
     :marked
       ### SystemJS Configuration
  +    ### SystemJS配置
   
       The QuickStart uses <a href="https://github.com/systemjs/systemjs" target="_blank">SystemJS</a>
         to load application and library modules. 
  
positive.code:   1. A static server called **lite-server** that loads `index.html` in a browser
    and refreshes the browser when application files change
  
    In a few moments, a browser tab should open and display
  
  figure.image-display
    img(src='/resources/images/devguide/quickstart/my-first-app.png' alt="Output of quickstart app")
  
  :marked
    Congratulations!  We are in business.
  
    ### Make some changes
    
    Try changing the message to "My SECOND Angular 2 app".
    
    The TypeScript compiler and `lite-server` are watching.
    They should detect the change, recompile the TypeScript into JavaScript,
    refresh the browser, and display the revised message.
  
    It's a nifty way to develop an application!
    
    We close the terminal window when we're done to terminate both the compiler and the server.
  
  .l-main-section
  :marked
    ## Final structure
    Our final project folder structure looks like this:
  .filetree
    .file angular2-quickstart
    .children
  
negative.code: 
      我们通过给这个组件类加上 **@Component** 前缀，并且传入metadata对象来使用它。
  
    +makeExample('quickstart/ts/app/app.component.ts', 'metadata', 'app/app.component.ts (元数据)')(format=".")
    :marked
      This particular metadata object has two fields, a `selector` and a `template`.
  
  