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        <title>菜鸟教程(runoob.com)</title> 
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            <h2>文本</h2>
            <p class="text-warning">该段落使用了样式 "text-warning"。</p>            
            <a class="text-warning" href="//www.w3cschool.cc">链接使用了样式 "text-warning"。</a>           
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