<!DOCTYPE html>
Test passes if
<table border="3" cellpadding="10">
  <td id=first>each cell</td>
  <td id=second>is in its</td>
  <td style="display: block;">own row.</td>
</table>
<script>
document.body.offsetHeight;
first.style.display = "block";
second.style.display = "block";
</script>