Beyond the answers - interesting background to this quiz

A novel that survived its own burning

Kurt Vonnegut's Slaughterhouse-Five draws directly on his experience as an American prisoner of war in Dresden during the Second World War, where he witnessed the firebombing of the city. The book mixes science fiction with autobiography, following the soldier Billy Pilgrim as he becomes "unstuck in time". Its anti-war message made it a target for censorship in some American schools, and copies have been publicly burned in protest.

The planet that barely has an atmosphere

Mercury is the smallest planet in the solar system and the closest to the Sun, yet it is not the hottest - Venus holds that record thanks to its thick, heat-trapping atmosphere. Mercury's own atmosphere is so thin that scientists often describe it as an exosphere, a loose scattering of atoms rather than a true layer of gas. Without that protective blanket, surface temperatures swing from scorching daylight to deeply frozen nights.

Where one continent ends and another begins

The Ural Mountains run roughly north to south through Russia and are conventionally treated as the boundary between Europe and Asia. The division is a human convention as much as a physical fact: the Urals are old, relatively low mountains, and the surrounding land is continuous. Geographers have argued for centuries about exactly where to draw the line, with the Ural River and the Caucasus also proposed as markers.

A cocktail with a disputed origin

The Margarita is built on tequila, usually with orange liqueur and lime juice, and served in a glass with a salted rim. Its beginnings are genuinely murky: several bartenders and socialites in Mexico and the United States have been credited with inventing it in the mid-twentieth century, and no single account has won general acceptance. What is clear is that it grew out of the earlier Daisy cocktail family, with tequila replacing the traditional base spirit.