Puzzles and quizzes

If your response to a mention of the Wars of the Roses, the Sumerians or the Reformation is, Hmm, Ive heard of that what was that again?

For those whose memories of learning science at school consist of burning magnesium and playing with iron filings and a magnet, and whose brains shut down as soon as things start to sound too technical, I Used to Know That: General Science is here to remind you of everything youve forgotten or should have learned.