anchor.diff:    :marked
       Focus on the following three TypeScript (`.ts`) files in the **`/app`** folder.
   
  -    注意**`/app`**目录里的下列三个 TypeScript (`.ts`) 文件：
  +    注意**`/app`**目录中以下三个 TypeScript (`.ts`) 文件：
     .filetree
       .file app
       .children
  
positive.code:   Make sure you have [!{_prereq} installed](#install-prerequisites "What if you don't have !{_prereq}?").
    Then ...
  
    确定你已经安装了[!{_prereq}](#install-prerequisites "如果你没有 !{_prereq} ？")，然后：
    
    1. Create a project folder (you can call it `quickstart` and rename it later).
  
  
negative.code: block includes
    include ../_util-fns
    - var _prereq = 'node and npm';
    - var _prereq_cn = 'node 和 npm';
    - var _playground = 'playground';
    - var _Install = 'Install';
    //- npm commands
  