<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <style>
        .wrap{
            border:2px solid red;
        }
       .wrap::after{      
            content:'';
            display:block;
            clear:both;
             
}
 .left {
    width: 100px;
    height: 100px;
    float:left;
    background:red;
    /*补全代码*/
    
}
 .right {
    width: 100px;
    height: 100px;
    float:left;
    background:blue;
    /*补全代码*/
    
}
    </style>
</head>

<body>
  <div class='wrap'>
	<div class='left'></div>
	<div class='right'></div>
</div>
    <script type="text/javascript">
        /* 填写JavaScript */
        
    </script>
</body>

</html>