W3School TIY
（请在下面的文本框中编辑您的代码，然后单击此按钮测试结果。）
编辑您的代码：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <style type="text/css"> p:first-child {font-weight: bold;} li:first-child {text-transform:uppercase;} </style> </head> <body> <div> <p>These are the necessary steps:</p> <ul> <li>Intert Key</li> <li>Turn key <strong>clockwise</strong></li> <li>Push accelerator</li> </ul> <p>Do <em>not</em> push the brake at the same time as the accelerator.</p> </div> <p><b>注释：</b>必须声明 DOCTYPE，这样 :first-child 才能在 IE 中生效。</p> </body> </html>
查看结果: