</p>
  <table>
   <tr>
    <td class="control">
     <div class="bg">
      <div class="a">A</div>
      <div class="c">C</div>
     </div>
    </td>
    <td>
     <div class="bg">
      <div class="a">A</div>
      <div class="b1"></div>
      <div class="c">C</div>
     </div>
    </td>
    <td>
     <div class="bg">
      <div class="a">A</div>
      <div class="b2"></div>
      <div class="c">C</div>
     </div>
    </td>
    <td>
     <div class="bg">
      <div class="a">A</div>
      <div class="b3">