Can we make more than two cells in a row with only one use of <tr> ?

Answer 1

Yes, just put more columns.

<table>
<tr>
<td>One</td>
<td>Two</td>
<td>Three</td>
</tr>
</table>

Answer 2

it's your wish. you can make as many as you want

Answer 3

You can use rowspan to achieve it!

Answer 4

yes you can add more than 2 cells. Cells are added using <td> tag and you may add as many of them as you require. structure might be

<table>
<tr>
<td> cell 01 </td>
<td> cell 02 </td>
<td> cell 03 </td>
<td> cell 04 </td>
</tr>
</table>