title: How to make bootstrap columns with images responsive
body: <p>For example if I have</p>
  
  <pre><code>&lt;style type="text/css"&gt;
  #box{
      height: 130px;
      background-color: red;
      margin: 10px;
  }
  &lt;/style&gt;
  &lt;div class="row"&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="row"&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="col-md-4"&gt;
          &lt;div id="box"&gt;&lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  </code></pre>
  
  <p>That will looked like</p>
  
  <pre><code>   box     box     box    
     box     box     box
  </code></pre>
  
  <p>Then after the window is resize it will become like this </p>
  
  <pre><code>   box  
     box
     box
     box
     box
     box
  </code></pre>
  
  <p>What I want is if I resize the window to lets say width of 766 pixels it will become like this</p>
  
  <pre><code>   box     box
     box     box 
     box     box
  </code></pre>
  
  <p>Then after a smaller window then it will become like</p>
  
  <pre><code>   box  
     box
     box
     box
     box
     box
  </code></pre>
  
  <p>I want it to be like 3 transformation.</p>