<title>Bootstrap 实例 - 进度条</title>
<link rel="stylesheet" href="/css/bootstrap/bootstrap3.3.7.min.css">
<script src="/js/bootstrap/jquery.min.js"></script>
<script src="/js/bootstrap/bootstrap3.3.7.min.js"></script>
<div class="progress-bar" role="progressbar" aria-valuenow="60"
aria-valuemin="0" aria-valuemax="100" style="width: 40%;">
<span class="sr-only">40% 完成</span>