一个有趣的js
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script src="https://code.jquery.com/jquery-3.0.0.min.js"></script>
<script>
var a='<div id="qq"><h1>wo shi h1</h1><input type="radio"/></div>';
setTimeout(function () {
$("body").append(a);
},100)
</script>
</body>
</html>
怎么能让这个单选框在添加到dom之前被选中