我看了好几遍，实在是不知道哪里有问题，请各位大神帮帮忙
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>使用CSS实现下拉菜单</title>
<style>
*{
margin: 0;
padding: 0;
}
ul li{
list-style: none;
}
.nav{
font-size: 14px;
font-weight: bold;
list-style: none;
}
/* 一级菜单 */
.nav li{
float: left;
margin-right: 1px;
}
.nav li a{
line-height: 34px;
text-decoration: none;
background: #3f240e;
color: #fff;
display: block;
width: 80px;
text-align: center;
}
.nav ul{
list-style: none;
display: none;
position: absolute;
}
.nav li a:hover{
background: url(images/slide-pannel_14.png) 0 0 repeat-x;
}
.note{
color: #3f240e;
display: block;
background: url(images/slide-pannel_14.png) 0 0 repeat-x;
}
</style>
<script src="js/jquery-1.9.1.js"></script>
<script>
$(document).ready(function(){
$(".nav li").mousemove(function(){
$(this).find("ul").slideDown("1000");
})
$(".nav li").mouseleave(function(){
$(this).find("ul").slideUp("slow");
})
})
</script>
</head>
<body>
<ul class="nav">
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