上周我在遇到问题时发布了一个类似的问题，但不确定我是否可以重新提出同一个问题，所以我创建了一个新问题以防万一。
我有两列，一列向左浮动，一列向右浮动，我正在使用 clear:both 来清除浮动，但它不起作用。我已经检查以确保我所有的 DIV 标签都已关闭并且它们已关闭（这是上次的问题）并将 clear:both 移动到不同的部分，但它仍然决定不工作。代码如下，但如果您想查看它的外观，可以在此处查看http://www.richardawarner.co.uk/portfoliov2
任何帮助表示赞赏。
HTML
<div id="sectiontwowrapper">
<div id="header">
<h1>About Me</h1>
</div><!--Header-->
<div id="contentwrapper">
<div id="aboutmeleft">
<h3>About Me</h3>
<br>
<a>My name is <strong>Richard Warner</strong> and I am a young web designer from Birmingham, United Kingdom. I have recently graduated from Manchester Metropolitan University having studied BSc(Hons) Multimedia Computing. Whilst having an interest in studying different aspects to computers, it was here where I developed a passion for web design. I have learnt various languages such as HTML, CSS and PHP aswell as experienced using Adobe Photoshop, Adobe Dreamweaver and other Adobe products.</a>
<p>
<h3>Skills and Expertise</h3>
<br>
<ul>
<li><a>HTML and CSS</a></li>
<li><a>PHP</a></li>
<li><a>MySQL</a></li>
<li><a>Wordpress</a></li>
<li><a>Adobe Photoshop</a></li>
<li><a>Adobe Dreamweaver</a></li>
</ul>
</div><!-- About me left -->
<div id="aboutmeright">
<h3>Hobbies</h3>
<br>
<a>Hobbies will appear here</a>
<p>
<h3>My CV</h3>
<br>
<a>You can download my CV by clicking here.</a>
</div><!-- About Me right -->
</div><!--Content Wrapper -->
</div><!--Section Two Wrapper -->
<div class="clear"></div>
<div id="sectionthreewrapper">
this line should be underneath this sections border line below
</div> <!--Section three wrapper -->
CSS
#sectiontwowrapper {
position: relative;
top: 100px;
min-height: 550px;
min-width: 960px;
text-align: left;
border: solid 1px #000;
#contentwrapper {
width: 960px;
margin: 0 auto;
text-align: left;
}
#aboutmeleft {
width: 450px;
height: 400px;
/*border: 1px solid #000;*/
position: relative;
top: 40px;
float: left;
}
#aboutmeright {
width: 450px;
height: 220px;
/*border: 1px solid #000;*/
position: relative;
top: 40px;
float: right;
}
.clear {
display: block;
clear: both;
}