How can I make a PHP 'foreach' loop repeat entire line?

Question

My objective is to allow users to select from check boxes and when they click submit it combines all PDFs into 1 PDF. (each check box has a PDF value).

<?php 
include 'PDFMerger.php';
$pdf = new PDFMerger;


$pdf1 = "/path/pdf1.pdf";
$pdf2 = "/path/pdf2.pdf";
?>

<form action="#" method="post">
<input type="checkbox" name="check_list[]" value="<?php echo $pdf1 ?>"><label>PDF ONE</label><br/>
<input type="checkbox" name="check_list[]" value="<?php echo $pdf2 ?>"><label>PDF TWO</label><br/>
<input type="submit" name="submit" value="Submit"/>
</form>


<?php

if(!empty($_POST['check_list'])){
foreach($_POST['check_list'] as $selected){

    $pdf->addPDF($selected);
}
}
?>
<?php
ob_start();

if(isset($_POST['submit'])){

$pdf->merge('download', 'TEST223.pdf');

}
?>

I am not a PHP expert at all, so I am sure there are many errors in the above code. But the problem lies with the 'foreach" area I think. It only repeats the $selected part.. not the entire line for each PDF.

So, if users select only 1 box.. it works fine. If they select more than one it puts the pdf path one after the other in the code and the Merger program can't use that.

//To visualize the issue.. I need the loop to produce this:
$pdf->addPDF("/path/pdf1.pdf");
$pdf->addPDF("/path/pdf2.pdf");
$pdf->addPDF("/path/pdf3.pdf");
etc...

//It is currently producing:
$pdf->addPDF("/path/pdf1.pdf/path/pdf2.pdf/path/pdf3.pdf");

Thank you for any help in advance.