test_form.php

<form name="deneme" method="POST" action="?yolla">
<select name="s_deneme">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select name="s_deneme2">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<input type="submit" name="gonder" value="Gönder">
</form>

<?php

if (isset($_GET['yolla'])) {

    echo $_POST['s_deneme'];
    echo "<br>";
    echo $_POST['s_deneme2'];

}
?>