哪里有错？咋只显示第一个？
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Math </title>
<script type="text/javascript">
document.write(Math.ceil(3.3) +"<br/>")
document.write(Math.cell(-0.1) +"<br/>")
document.write(Math.ceil(-9.9) +"<br/>")
document.write(Math.ceil(8.9) +"<br/>")
</script>
</head>
<body>
</body>
</html>
