为什么99会弹出一列
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>使用thead、tbody、tfoot标签</title>
</head>
<body>
<h2>成绩表</h2>
<hr>
<table border='1'>
<thead>
<tr>
<th>科目</th>
<th>分数</th>
</tr>
</thead>
<tbody>
<tr>
<td>语文<td>
<td>99</td>
</tr>
<tr>
<td>数学</td>
<td>60</td>
</tr>
</tbody>
<tfoot>
<tr>
<td>总分</td>
<td>159</td>
</tr>
</tfoot>
</table>
</body>
</html>
