<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style>
div.test {
200px; /*宽度*/
float: left; /*向左漂浮*/
}
div.clear { clear: both } /*用于清除浮动*/</style>
</HEAD>
<BODY>
<div>
<div class="test">第一层</div>
<div class="test">第二层</div>
<div class="test">第三层</div>
</div>
<div class="clear"></div>
<div class="test">第四层</div>
</BODY>
</HTML>