Beyond the answers - interesting background to this quiz

The rhapsody that made a pianist a star

Franz Liszt wrote his nineteen Hungarian Rhapsodies between roughly 1846 and 1885, drawing on folk and gypsy melodies he had heard in his native Hungary. The second rhapsody is the most famous, largely thanks to its slow, brooding opening and the frantic finale that follows. Liszt was one of the great virtuoso pianists of the nineteenth century, and the rhapsodies were partly built to show off exactly that kind of fireworks.

A belt of land on the edge of the desert

Burkina Faso sits in the Sahel, the semi-arid strip that runs across Africa just south of the Sahara. The name comes from the Arabic word for "shore" or "coast", since the region was long imagined as the coastline of the great desert. The Sahel stretches from the Atlantic coast eastward toward the Red Sea, passing through countries such as Senegal, Mali, Niger and Chad. Rainfall there is unpredictable, which shapes both farming and daily life.

A vitamin your own bacteria make

Vitamin K is unusual because the body can get some of it from the bacteria living in the gut, not just from food. Leafy greens such as spinach and kale are the best-known dietary sources, while the gut bacteria contribute an extra supply. Vitamin K matters for blood clotting, which is why newborns are often given a dose shortly after birth.

A declaration that started as an argument

The Declaration of Independence was adopted by the Continental Congress on July 4, 1776, but the vote for independence had actually taken place two days earlier. Thomas Jefferson drafted the document, and it was edited by others before approval. The famous lines about life, liberty and the pursuit of happiness turned a political break into a statement of principle that still gets quoted today.