我想在WordPress中添加3列引导菜单，但我无法做到这一点。我已经尝试了很多，但子菜单和列不是显示。谁能帮帮我吗。
这是我的引导代码。
<nav class="navbar navbar-default" role="navigation">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
<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="<?php bloginfo('url')?>">
<img alt="Brand" src="img/is-logo.png">
</a>
</div>
<!--/.navbar-header-->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Information <b class="caret"></b></a>
<ul class="dropdown-menu multi-column columns-3">
<div class="row">
<div class="col-sm-4">
<ul class="multi-column-dropdown">
<li><a href="#"><span class="icon-airplane"></span> Airlines</a></li>
<li><a href="#"><span class="icon-github"></span> Animal</a></li>
<li><a href="#"><span class="icon-apple"></span> Apple</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_Bangladesh"><span class="path1"></span><span class="path2"></span></span>
Bangladesh
</a>
</li>
<li><a href="#"><span class="icon-twitter"></span> Birds</a></li>
<li><a href="#"><span class="icon-droplet"></span> Blood</a></li>
<li><a href="#"><span class="icon-git-cat"></span> Cat</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_China"><span class="path1"></span><span class="path2"></span><span class="path3"></span><span class="path4"></span><span class="path5"></span><span class="path6"></span><span class="path7"></span><span class="path8"></span><span class="path9"></span><span class="path10"></span><span class="path11"></span><span class="path12"></span><span class="path13"></span><span class="path14"></span><span class="path15"></span><span class="path16"></span><span class="path17"></span><span class="path18"></span><span class="path19"></span><span class="path20"></span><span class="path21"></span><span class="path22"></span><span class="path23"></span></span>
China
</a>
</li>
<li>
<a href="#">
<span class="icon-Flag_of_Denmark">
<span class="path1"></span><span class="path2"></span><span class="path3"></span>
</span>Denmark
</a>
</li>
<li><a href="#"><span class="icon-library"></span> Education</a></li>
</ul>
</div>
<div class="col-sm-4">
<ul class="multi-column-dropdown">
<li><a href="#"><span class="icon-airplane"></span> Airlines</a></li>
<li><a href="#"><span class="icon-github"></span> Animal</a></li>
<li><a href="#"><span class="icon-apple"></span> Apple</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_Bangladesh"><span class="path1"></span><span class="path2"></span></span>
Bangladesh
</a>
</li>
<li><a href="#"><span class="icon-twitter"></span> Birds</a></li>
<li><a href="#"><span class="icon-droplet"></span> Blood</a></li>
<li><a href="#"><span class="icon-git-cat"></span> Cat</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_China"><span class="path1"></span><span class="path2"></span><span class="path3"></span><span class="path4"></span><span class="path5"></span><span class="path6"></span><span class="path7"></span><span class="path8"></span><span class="path9"></span><span class="path10"></span><span class="path11"></span><span class="path12"></span><span class="path13"></span><span class="path14"></span><span class="path15"></span><span class="path16"></span><span class="path17"></span><span class="path18"></span><span class="path19"></span><span class="path20"></span><span class="path21"></span><span class="path22"></span><span class="path23"></span></span>
China
</a>
</li>
<li>
<a href="#">
<span class="icon-Flag_of_Denmark">
<span class="path1"></span><span class="path2"></span><span class="path3"></span>
</span>Denmark
</a>
</li>
<li><a href="#"><span class="icon-library"></span> Education</a></li>
</ul>
</div>
<div class="col-sm-4">
<ul class="multi-column-dropdown">
<li><a href="#"><span class="icon-airplane"></span> Airlines</a></li>
<li><a href="#"><span class="icon-github"></span> Animal</a></li>
<li><a href="#"><span class="icon-apple"></span> Apple</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_Bangladesh"><span class="path1"></span><span class="path2"></span></span>
Bangladesh
</a>
</li>
<li><a href="#"><span class="icon-twitter"></span> Birds</a></li>
<li><a href="#"><span class="icon-droplet"></span> Blood</a></li>
<li><a href="#"><span class="icon-git-cat"></span> Cat</a></li>
<li>
<a href="#">
<span class="icon-Flag_of_China"><span class="path1"></span><span class="path2"></span><span class="path3"></span><span class="path4"></span><span class="path5"></span><span class="path6"></span><span class="path7"></span><span class="path8"></span><span class="path9"></span><span class="path10"></span><span class="path11"></span><span class="path12"></span><span class="path13"></span><span class="path14"></span><span class="path15"></span><span class="path16"></span><span class="path17"></span><span class="path18"></span><span class="path19"></span><span class="path20"></span><span class="path21"></span><span class="path22"></span><span class="path23"></span></span>
China
</a>
</li>
<li>
<a href="#">
<span class="icon-Flag_of_Denmark">
<span class="path1"></span><span class="path2"></span><span class="path3"></span>
</span>Denmark
</a>
</li>
<li><a href="#"><span class="icon-library"></span> Education</a></li>
</ul>
</div>
</div>
</ul>
</li>
</ul>
</div>
</div>
</nav>