html中的rowspan和colspan

摘自w3school（http://www.w3school.com.cn/tags/att_td_colspan.asp）
colspan 属性规定单元格可横跨的列数。
<table border="1">
  <tr>
    <th>Month</th>
    <th>Savings</th>
  </tr>
  <tr>
    <td colspan="2">January</td>
  </tr>
  <tr>
    <td colspan="2">February</td>
  </tr>
</table>
rowspan 属性规定单元格可横跨的行数。

<table border="1">
  <tr>
    <th>Month</th>
    <th>Savings</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$100.00</td>
    <td rowspan="2">$50</td>
  </tr>
  <tr>
    <td>February</td>
    <td>$10.00</td>
  </tr>
</table>