<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8"> 
        <title>菜鸟教程(runoob.com)</title> 
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">  
        <script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
        <script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
    </head>
    <body>

        <div class="container">
            <h2>代码</h2>
            <p>使用 kbd 元素表示按键输入:</p>
            <p>使用 <kbd>ctrl + p</kbd> 来打开打印窗口。</p>
        </div>

    </body>
</html>