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<html>
    <head>
        <meta charset="utf-8"> 
        <title>菜鸟教程(runoob.com)</title> 
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        <div class="container">
            <h2>实例</h2>
            <div class="pull-left">元素浮动到左侧</div>
            <div class="pull-right">元素浮动到右侧</div>
        </div>

    </body>
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