It needed a root canal.
or
One's a spineless, poisonous blob. The other is a form of sea life.
or
Nearly unanswerable, since the one who tries to change it usually drops it, and the others call for a planning session.
or
Just one, but he/she will spend hours checking for technical problems.
or
Mt Rushmore. They're a rock group.. it's a rock...group
or
He made sure his pools were clean and his lawns were mowed.
or