Let say I got this page:
假设我有这个页面:
<body>
<h1>Hello!</h1>
<div class="wrapper">
<div class="anotherclass">
<h1>Another heading 1</h1>
</div>
<div class="yetanotherclass">
<h1>Yet another heading 1</h1>
</div>
</div>
<h1>Good bye!</h1>
<div class="class">
<h1>Good bye. And this time I mean it.</h1>
</div>
</body>
<body>
