"That's an old riddle, but I'm not sure I take your meaning."

The old riddle raises an issue of real importance to many animal species, and to the scientists who study them.

There is an old riddle about an island with two tribes.

Well, what's the answer to the old riddle?

Smiles, according to an old riddle, may be considered the longest word in English, as there is a mile between the first and last letter.

Books, like newspapers in the words of the old riddle, are black and white and read all over.

Alone hi his room, he tried again to come to grips with that old riddle of the three days missing from his life.

The chicken turns to the egg and says, well, I think you've just answered that old riddle.

But now comes a riddle more than a hundred years old!

Never found the answers to half the old riddles.