老师，我的下拉菜单出不来，而且网页缩小后右上角可以出现导航栏那个图标，但是点击的时候不会把隐藏的综述、简述、关于等这些标题显示出来，点击没反应。请问老师这个有可能是什么原因？？
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width,initial-scale=1" />
<title></title>
<link href="bootstrap/css/bootstrap.css" rel="stylesheet" />
</head>
<body>
<%-- <form id="form1" runat="server">
<nav class="navbar navbar-default" role="navigation">
<div class="container-fluid">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="navbar-responsive-collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">首页</a>
</div>
<div class="collapse navbar-collapse navbar-responsive-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">active</a></li>
<li><a href="#">Link</a></li>
<li class="disabled"><a href="#">disabled</a></li>
<li><a href="#">Link</a></li>
</ul>
</div>
</div>
</nav>
</form>--%>
<nav class="navbar navbar-default navbar-fixed-top">
<div class="container-fluid">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Link <span class="sr-only">(current)</span></a></li>
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">Separated link</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</ul>
</div><!-- /.navbar-collapse -->
</div><!-- /.container-fluid -->
</nav>
<script src="bootstrap/js/jquery-1.8.2.js"></script>
<script src="bootstrap/js/bootstrap.js"></script>
</body>
</html>
