怎么分数显示不出来
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>系好安全带,准备启航</title>
<script type="text/javascript">
var my=new Date()
//通过javascript的日期对象来得到当前的日期，并输出。
var weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"]
var motch=["一月","二月","三月","四月","五月","六月","七月","八月","九月","十月","十一月","十二月",]
document.write(my.getFullYear()+"年"+motch[my.getMonth()]+my.getDate()+"号"+weekday[my.getDay()])
//成绩是一长窜的字符串不好处理，找规律后分割放到数组里更好操作哦
var scoreStr = "小明:87;小花:81;小红:97;小天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76";
var mn=scoreStr.split("；")
var sum=0
for(var i=0;i<mn.length;i++)
{sum=sum+parseINt(mn.slice(3,5))}
//从数组中将成绩撮出来，然后求和取整，并输出。
var sum1=sum/mn.length
document.write("班级总分为："+sum+"班级平均分为："+Math.round(sum1))
</script>
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<body>
</body>
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