<table align= "center">
<tr align="center" valign="middle"><td>
<input name="text_l0" type="text" id="l0" size="7" maxlength="15" />
<select name="l0">
<option value="n, mol" selected="selected">n, mol</option>
<option value="V, l">V, l</option>
<option value="m, g">m, g</option>
</select></td>
<td></td>
<td>
<input name="text_l1" type="text" id="l1" size="7" maxlength="15" />
<select name="l1">
<option value="n, mol" selected="selected">n, mol</option>
<option value="V, l">V, l</option>
<option value="m, g">m, g</option>
</select></td>
<td></td><td>
<input name="text_r0" type="text" id="r0" size="7" maxlength="15" />
<select name="r0">
<option value="n, mol" selected="selected">n, mol</option>
<option value="V, l">V, l</option>
<option value="m, g">m, g</option>
</select></td></tr>
<tr align="center" valign="middle"><td>
<h3>2H<sub>2</sub></h3></td>
<td><h3>  +  </h3></td>
<td>
<h3>O<sub>2</sub></h3></td>
<td>=</td><td>
<h3>
2H<sub>2</sub>O</h3></td></tr>
<tr align="center" valign="middle">
<td></td>

<td></td>

<td></td>

<td></td>
<td></td>

<td></td>
</table>