A.<table> <tr> <td>单元格1</td> </tr> <tr> <td>单元格2</td> </tr> </table>
B.<table> <tr> <tr>单元格1</tr> </tr> <tr> <tr>单元格2</tr> </tr> </table>
C.<table> <td> <tr>单元格1</tr> <tr>单元格2</tr> </td> </table>
D.<table> <tr> <td>单元格1</td> <td>单元格2</td> </tr> </table>