OK so here goes with my answer to the second of our fourth series of questions. Ready? … Go …

Question 2: Why are manhole covers round?
I’m so surprised at even having to be asked this, as I would have thought the answer was obvious: as a safeguard against square aliens, of course.
I mean what other possible reason could there be? It isn’t as if they’re really easier to make than heptagonal covers, is it? Nor easier than square ones.
And it can’t be that a round cover would use less material than a polygonal one, can it. That would just be silly! How could any right-minded person think such a thing?
No the only possible answer is that they’re to guard against square alien invaders …

See what I mean?