这个是怎么执行的呢，望具体解析O(∩_∩)O~~

<table border="1px">

<?php

for ($c=1;$c<=9;$c++){

echo "<tr>";

for ($d=$c;$d<=9;$d++){

echo "<td align='right'>";

echo $c."x".$d."=".$c*$d."&nbsp;&nbsp;&nbsp;";

echo "</td>";

}

echo "</tr>";

echo "<tr/><tr/>";

}

?>

</table>