console 命令行工具 X clear
console
<!DOCTYPE html>
<html>
<head>
  <title>Bootstrap 实例</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.1.0/css/bootstrap.min.css">
  <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
  <script src="https://cdn.bootcss.com/popper.js/1.12.5/umd/popper.min.js"></script>
  <script src="D:/安装包/bootstrap-4.1.3/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
  <h1>我的第一个 Bootstrap 页面</h1>
  <p>这是一些文本。</p> 
</div>

</body>
</html>