text: import React from "react";
  import {BrowserRouter, Route, Link} from 'react-router-dom';
  
  class Grade extends React.Component{
      render(){
          return(
              <div id="introduction">
                  <h1>高级用法</h1>
                  <hr/>
                  <li><Link to="/" style={{color: "#4183c4"}}>动态路由</Link></li>
                      <li><Link to="/react" style={{color: "#4183c4"}}>路由匹配原理</Link></li>
                      <li><Link to="/react" style={{color: "#4183c4"}}>服务端渲染</Link></li>
                      <li><Link to="/react" style={{color: "#4183c4"}}>模块生命周期</Link></li>
                      <li><Link to="/react" style={{color: "#4183c4"}}>组件外部跳转</Link></li>
              </div>
          )
      }
  }
  export default Grade;