我的代码：
<style>
select#gender option[value="male"] {background-image:url(images/slidee3.jpg)}
select#gender option[value="female"] {background-image:url(images/slidee4.jpg);}
select#gender option[value="others"] {background-image:url(images/slidee4.jpg);}
</style>
</head>
<body>
<select id="gender">
<option value="male" selected="selected">male</option>
<option value="female">female</option>
<option value="others">others</option>
</select>
</body>