title: Materialize - dropdown doesn't work
body: <p>I am using materialize framework for ui design. If you look at my <a href="http://plnkr.co/edit/NOxHehqbtvK0lTZ5uGVs" rel="nofollow">code</a> , the dropdown doesn't show. Please help.</p>
  
  <pre><code>&lt;div class="input-field col s3"&gt;
      &lt;select&gt;
          &lt;option value="" disabled selected&gt;Choose your option&lt;/option&gt;
          &lt;option value="1"&gt;USD&lt;/option&gt;
          &lt;option value="2"&gt;CAD&lt;/option&gt;
          &lt;option value="3"&gt;HDK&lt;/option&gt;
      &lt;/select&gt;
      &lt;label&gt;Select Currency&lt;/label&gt;
  &lt;/div&gt;
  </code></pre>