Hard Quiz — Episode 5: William Wallace, The Wizard of Oz, Black Holes & Mammalian Sperm

You are watching the episode William Wallace, The Wizard of Oz, Black Holes & Mammalian Sperm Tom Gleeson has the questions. Do our experts have the answers? Tonight's topics include William Wallace, The Wizard of Oz, black holes and mammalian sperm. Play along with Hard Quiz!