先看一段代码：
<!DOCTYPE html>
<html>
<head>
<title>文本节点</title>
</head>
<body>
<ul id="list1">
<li>1</li>
<li>2</li>
<li>3</li>
</ul>
<ul id="list2"><li>1</li><li>2</li><li>3</li></ul>
<script type="text/javascript">
<!DOCTYPE html>
<html>
<head>
