Select 2 on bootstrap 3

There is some way to use select2 in Bootstrap 3.3, terial some example to try to implement, I'm building my TCC on the adminLTE template and needed something like it in some queries, thank you!

I was able to implement this way:

<div class="form-horizontal">
      <label class="required-inputs"><b>Descrição</b></label>
      <select id="select2-ex" name="state" style="width: 100%;">
           @foreach($professores as $p)
                <option value="{{$p->id}}">{{$p->nome}}</option>
           @endforeach
       </select></div>

JQuery:

$(document).ready(function() {
    $('#select2-ex').select2();
});

How can I return more than one item?