table表格、tr行、td单元格、th表头单元格、表格标题caption
thead、tbody
合并单元格：跨行合并rowspan、跨列合并colspan
<table width="500" border="0" align="center" cellspacing="0" cellpadding="0">
<caption>***</caption>
<tr>
<td></td>
<td></td>
<td></td>
</tr>
</table>
