第二次发布作业测试
<!DOCTYPE html>
<html>
<head>
<mate charset="utf-8">
<title>html+css布局</title>
<style type="text/css">
*{margin:0;padding:0}
table{table-layout:fixed;width:600px;margin:10px auto;border:1px #000000 solid;background:#CFEFEF;}
</style>
</head>
<body>
<table><th>列标题1</th><th>列标题2</th><th>列标题3</th>
<tr><td>1</td><td>2</td><td>3</td></tr></table></body>
</html>