3个同一行div的摆放div

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  <title>3个同一行div的摆放div</title>
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 <body>
 <div style="100%;height:200px;border:1px solid red;margin:50px 0px;">
<div style="300px;height:100px;border:1px solid red;float:left;">我是left div标签</div> 
<div style="300px;height:100px;border:1px solid red;float:right;">我是right div标签</div>
<div style="300px;height:100px;border:1px solid red; margin:0px auto;">我是center div标签</div>
</div>
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如果同一行要摆放5个div则在3个的基础上通过float:right/left; margin进行控制