关于 hover 的用法
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.<html xmlns="http://www.
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
.div1{width:200px;height:200px;background-color: blue;}
.div2{width:200px;height:200px;background-color: yellow;}
.div1:hover ~div{background-color: red;}/*为什么用~div呢?*/
/*.div1:hover .div2{background:#90F;} 为什么此句不可以呢?*/
</style>
</head>
<body>
<div class="div1"></div>
<div class="div2"></div>
</body>
