PHP延迟循环

Is it possible to have a random delay in a loop to process each item? and if so does that affect the php timeout?

I want the random number to occur for each item e.g. first item may have a sleep of 5, whilst next will be 10.

I know the code for random number for 10-100 is below:

$random = (rand(10,100));

However, where do I put this in my code, because I want it to change for each loop.

Also the code to sleep, where would that go:

sleep($random);

Here is my code

<?php
        foreach ($ret as $l) {

            $id_s = $l['idx'];
            $from_s = $l['number'];
            $msg_s = $l['msg'];
            $timestamp = date("F j, Y, g:i a");



            $url = 'index.php?service=insertMsgs&timestamp='.$timestamp.'&from='.$from_s.'&msg='.$msg_s;
            echo $url;
            $ch = curl_init();  
            curl_setopt($ch,CURLOPT_URL,$url);
            curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
            $output=curl_exec($ch);
            curl_close($ch);
            $this->deleteSms($id_s);
            print_r($output);       
        }

?>