php - Some URLs cant be connected by cURL -

i making php web crawler using curl. can content of every url except urls belonged this website. browser kept loading , no result returned. here code

    $chs = array();     $content = array();     $cmh = curl_multi_init();      ($i = 0; $i < $max; $i++)     {         $chs[$i] = curl_init();         curl_setopt($chs[$i], curlopt_url, $url_list[$i]);         curl_setopt($chs[$i], curlopt_returntransfer,true);         curl_setopt($chs[$i], curlopt_followlocation, 1);         curl_multi_add_handle($cmh, $chs[$i]);     }      $running=null;     {         $status = curl_multi_exec($cmh, $running);     } while ($running > 0);      ($i = 0; $i < $max; $i++)     {         $content[$i] = curl_multi_getcontent($chs[$i]);         curl_close($chs[$i]);     }     curl_multi_close($cmh);