<html>
<head>
<style>
h1.one
{
visibility:visible;
}
h1.two
visibility:hidden;
</style>
</head>
<body>
<h1 class="one">标题 一</h1>
<h1 class="two">标题 二</h1>
<p>标题二在哪儿？</p>
</body>
</html>