title: Bootstrap col-*
body: <p>I have simple question - I have such code:</p>
  
  <pre><code>&lt;div class="col-lg-12 col-md-12 col-sm-12 col-xs-12"&gt;...&lt;/div&gt;
  </code></pre>
  
  <p>Do I need to use all cols, if they are the same or I can use only one of col-* class?</p>