显示不出来？

源自：2-6 编程练习

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<head>

<title>无标题文档</title>

*{padding:0;margin:0;}

.mainBox{width=960px;height=300px;background-color:#CFF;overflow:visible;}

.leftBox{width=740px;height=300px;background-color:#C9F;float:left;}

.rightBox{width=210px;height=300px;background-color:#FCF;float:right;}

.clear

{

clear:both;

height:0;/*解决IE6下有高度的问题*/

overflow:hidden;}

</style>

</head>

<body>

</div>

</body>

</html>

提问者：慕粉3809774 2016-09-25 16:24