兼容ie6及一下版本的自适应

<meta http-equiv="X-UA-Compatible" content="IE=edge,Chrome=1" />
<meta http-equiv="X-UA-Compatible" content="IE=9" />
    <!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
    <!--[if lt IE 9]>
    <script src="http://apps.bdimg.com/libs/html5shiv/3.7/html5shiv.min.js"></script>
    <script src="http://apps.bdimg.com/libs/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->