How can I show only first li and hide the others?

I am trying to do a combobox via jQuery:

My jQuery script:

var drp = $('.drpdiv');

    $(drp).each(function(index,value){

            $(this).find('li:first').text()
            $(this).find('li').hide();
            alert($(this).find('li:first').text());

    });

My html code:

<div class="drpdiv">
    <ul class="drp">
        <li>select option...</li>   
        <li>one</li>
        <li>two</li>
        <li>three</li>
    </ul>
</div>