console
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Bootstrap 实例 - 基本的按钮下拉菜单</title>
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle"
data-toggle="dropdown">
<span class="glyphicon glyphicon-chevron-up"></span> 上钻
</button>
<ul class="dropdown-menu" role="menu">
<li><a href="#">省</a></li>
<li><a href="#">市</a></li>
<li><a href="#">县</a></li>
</ul>
</div>
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
<span class="glyphicon glyphicon-chevron-down"></span> 下钻
</button>
<ul class="dropdown-menu" role="menu">
<li><a href="#">省</a></li>
<li><a href="#">市</a></li>
<li><a href="#">县</a></li>
</ul>
</div>
</body>
</html>