<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title></title>
<style type="text/css">
*{margin: 0;padding: 0;text-align: center;line-height: 100px;}
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ul li{width: 200px;height: 100px;background: yellow;margin-bottom: 20px;font-size: 12px;color: blue;border: 2Px solid pink;}
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for(var i=0;i<Li.length;i++){
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var Li1=document.getElementById('li1');
var Li2=document.getElementById('li2');
var Li3=document.getElementById('li3');
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</head>
<body>
<ul>
<li id='li1'>么么哒</li>
<li id='li2'>啦啦啦</li>
<li id='li3'>啪啪啪</li>
</ul>
</body>
</html>
