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<html>
<head>
<meta charset="utf-8">
<title>W3Cschool(w3cschool.cn)</title>
</head>
<body>
<p id="p1">Hello World!</p>
<script src="/statics/demosource/demo_async.js" async></script>
<p><strong>注意:</strong>Internet Explorer 9 及之前的版本不支持 script 标签的 async 属性。</p>
</body>
</html>