请问如何实现如下效果。

Question

<table border="1">
<tr>
<td rowspan="2">1</td>
<td rowspan="2">2</td>
<td colspan="3">3</td>
</tr>
<tr><td>3</td>
<td>4</td>
<td>5</td>
</tr>
</table>

Answer 1

我原来的是这样写的啊。
但是colspan这列无css样式了。不知道为何。

Answer 2

 <thead>
                    <tr>
                            <th rowspan="2">1</th>
                            <th  rowspan="2">2</th>
                            <th  rowspan="2">3</th>
                            <th  rowspan="2">4</th>
                            <th  rowspan="2">5</th>
                            <th  rowspan="2">6</th>
                            <th  rowspan="2">7</th>
                            <th  rowspan="2">8</th>
                            <th  colspan="4">9</th>
                        </tr>
                        <tr>
                            <th>10</th>
                            <th>11</th>
                            <th>12</th>
                            <th>13</th>
                        </tr>
                    </thead>