Beyond the answers - interesting background to this quiz

The river that drains a continent

The Volga flows entirely through Russia and is the longest river in Europe. It rises in the Valdai Hills north-west of Moscow and empties into the Caspian Sea, the largest inland body of water on Earth. Along the way it passes through cities such as Nizhny Novgorod, Kazan and Volgograd, and it is often described as Russia's national river.

A moon that hints at an ocean

Europa is one of Jupiter's largest moons, and its surface is a shell of ice criss-crossed by long cracks. Beneath that ice, scientists believe, lies a salty ocean. Because liquid water is a key ingredient for life as we know it, Europa has become one of the most studied bodies in the Solar System, and space agencies have planned missions to investigate it.

The waltz that became an unofficial anthem

Johann Strauss II composed "The Blue Danube" in 1866, and it grew into one of the most recognisable pieces of classical music. Its gentle opening and sweeping melodies capture the elegance of the Viennese waltz. The river it celebrates runs through Vienna and several other Central European capitals, and the piece is still performed at New Year's concerts around the world.

A flower born from grief

In Greek myth, Adonis was a youth of extraordinary beauty loved by Aphrodite. When he was killed by a boar, the goddess turned his blood into an anemone, a flower that blooms briefly and is scattered by the wind. The story became a symbol of beauty that is intense but short-lived, a theme repeated throughout classical literature and art.

The element named after a village

Erbium takes its name from Ytterby, a small Swedish village where several rare-earth elements were first identified. Its chemical symbol is Er, and it sits among the lanthanides on the periodic table. Erbium has practical uses too: it is added to glass and fibre-optic cables, and erbium-doped amplifiers help carry signals across long-distance communication networks.