anchor.diff:  
   .l-main-section
   h2#index Step !{step++}: Add #[code index.html]
  -h2#index 步骤!{step++}：添加#[code index.html]
  +h2#index 步骤5：添加#[code index.html]
   :marked
     In the *#{_indexHtmlDir}* folder
     create an `index.html` file and paste the following lines into it:
  
positive.code: 
  .l-main-section#build-and-run
  h2 Step !{step++}: Build and run the app!
  h2 步骤!{step++}：构建并运行本应用！
  block run-app
    :marked
      Open a terminal window and enter this command:
  
negative.code:   .l-main-section#ngmodule
    :marked
      ## Step 3: Our own `app.module.ts`
      ## 步骤3：创建`app.module.ts`
  
      We compose Angular apps into closely related blocks of functionality with [Angular Modules](guide/ngmodule.html).
      Every app requires at least one module, the _root module_, that we call `AppModule` by convention.
  