Beyond the answers - interesting background to this quiz

The country that keeps turning up on other people's borders

France shares land borders with seven countries, and three of them are named in this quiz's first question: Italy, Spain and Belgium. That makes France the answer, but the geography behind it is more interesting than the label. The border with Spain runs largely along the Pyrenees, while the Italian frontier climbs through the Alps. The Belgian border, by contrast, cuts across flat, densely populated land that has shifted many times over the centuries.

An oversized rodent with a surprising family tree

The capybara is the world's largest living rodent, a semi-aquatic grazer native to South America. It can weigh as much as a small adult human, which makes its closest relatives - guinea pigs and rock cavies - seem almost comically small by comparison. Capybaras live in social groups near rivers and wetlands, and they are unusual among rodents for the way they chew and digest tough aquatic plants.

A river that crosses borders and powers a waterfall

The Zambezi is southern Africa's fourth-longest river and one of the continent's most important waterways. It rises in Zambia and flows through several countries before emptying into the Indian Ocean in Mozambique. Along the way it plunges over Victoria Falls, a waterfall so large that its spray can be seen from kilometres away. The river also feeds major hydroelectric schemes, making it both a natural wonder and an economic lifeline.

Why Jupiter's day is so short

Jupiter has the shortest day of any planet in the Solar System, spinning once on its axis in under ten hours. That speed is remarkable given the planet's enormous size, and it is not without consequences: the rapid rotation flattens Jupiter slightly at the poles and helps drive its banded cloud patterns. By contrast, Earth takes roughly twenty-four hours and Mars a little longer, so Jupiter wins this particular race comfortably.

Two boys who trade places

Mark Twain's The Prince and the Pauper pairs Tom Canty, a poor London boy, with Prince Edward, the heir to the throne. The two discover they look identical and swap clothes, setting off a chain of mistaken identities that tests both of them. Twain wrote the novel in the 1880s, and it remains one of his best-known works outside the adventures of Tom Sawyer and Huckleberry Finn.