you would need to create an if statement to check all 6 form elements:
<?php if($_POST["school_6"] != "" && $_POST["usdf_6"] != "" && $_POST["breed_6"] != "" && $_POST["iea_6"] != "" && $_POST["usef_6"] != "" && $_POST["rifna_6"] != "") { ?>
<br />
<?php echo((isset($_POST["school_6"]))?$_POST["school_6"]:"") ?><br />
<?php echo((isset($_POST["usdf_6"]))?$_POST["usdf_6"]:"") ?><br />
<?php echo((isset($_POST["breed_6"]))?$_POST["breed_6"]:"") ?><br />
<?php echo((isset($_POST["iea_6"]))?$_POST["iea_6"]:"") ?><br />
<?php echo((isset($_POST["usef_6"]))?$_POST["usef_6"]:"") ?><br />
<?php echo((isset($_POST["rifna_6"]))?$_POST["rifna_6"]:"") ?><br />
<?php } ?>