两个div图片不换行

miain.css
#main_body {
width: 1024px;
height: 720px;
background: url("../images/beijing.jpg") no-repeat scroll;
margin: auto;
border: #000;
}
#zuo {
width: 140px;
height: 720px;
background: url(../images/98df95513bb96e91f18455ba959a0834.jpg);
}
#shang {
width: 744px;
height: 140px;
background: url(../images/98df95513bb96e91f18455ba959a0834.jpg);
position: relative;
}
<html>
<head>
<link rel="stylesheet" href="css/main.css" />
</head>
<body>
<div id="main_body">
<div id="zuo"> </div>
<div id="shang"></div>
</div>

</body>
</html>
position: relative;怎么不起作用，加上去图片都不显示

举报该文章