<script type="text/jscript">for(var i=5;i>=1;i--){ for(var n=1;n<=i;n++){ document.write("*"); } document.write("<br>"); } for(var i=1;i<=5;i++){ for(var n=1;n<=i;n++){ document.write("*"); } document.write("<br>"); }var scores=new Array(98,77,56,91,89,76);var count=0;for(var i=0; i<scores.length;i++){ count=count+scores[i]; } document.write("总和是"+count+"<br>"); count=count/scores.length; document.write("平均和是"+count);</script>求怎样为同学讲题越清楚越好