Select Drop Down Does Not Work In Mobile Device When Apply Bootstrap

I'm using html select in the bootstrap col, but when i click drop down button in the mobile device(iOS and Android), it can not display the option list. But it works in the PC brow

Solution 1:

Try using like this

<form role="form">
   <div class="form-group">
      <div class="col-xs-6 col-sm-6 col-md-6">     
        <select class="form-control">
         <option>1</option>
         <option>2</option>
         <option>3</option>
         <option>4</option>
         <option>5</option>
        </select>
       </div>
    <div class="col-xs-6 col-sm-6 col-md-6">
      <select class="form-control">
         <option>1</option>
         <option>2</option>
         <option>3</option>
         <option>4</option>
         <option>5</option>
      </select>
    </div>
    </div>
</form>

Working fiddle http://jsfiddle.net/52VtD/9092/