Beyond the answers - interesting background to this quiz

The marathon that turned a legend into a mass event

The London Marathon is a running event, first held in 1981, and it has grown into one of the largest annual marathons in the world. Its flat, fast course winds past landmarks such as Tower Bridge and the Houses of Parliament, which is one reason it attracts both elite record chasers and thousands of charity runners. The race distance itself, 42.195 kilometres, commemorates the legendary run of the Greek soldier Pheidippides from Marathon to Athens.

Why carbon dioxide smothers flames

Carbon dioxide extinguishers work by displacing oxygen around a fire and, on some models, cooling the fuel as the gas expands. Because CO2 leaves no residue, it is a common choice for electrical equipment and laboratories. It is not a universal solution, however: it is a poor fit for fires involving cooking oils or certain metals, where other agents are required.

A walled city on the Adriatic

Dubrovnik sits on the Adriatic Sea, the arm of the Mediterranean that separates the Italian peninsula from the Balkan peninsula. Its medieval walls, largely intact and walkable, once protected a prosperous trading republic. Today the old town is a UNESCO World Heritage Site, and its distinctive rooftops have made it a familiar backdrop on screen as well as in person.

Ottawa: a capital chosen to keep the peace

Ottawa, not Toronto or Vancouver, is the capital of Canada. Queen Victoria selected the then-small lumber town in 1857 partly because it sat on the border between English-speaking Ontario and French-speaking Quebec, making it a compromise that neither side could begrudge. The city's Parliament Hill, set above the Ottawa River, remains the symbolic centre of the country.

The boy raised by wolves

Mowgli, the child who grows up among animals, is the central figure of Rudyard Kipling's The Jungle Book, published in 1894. The stories of Baloo, Bagheera and Shere Khan have been retold in countless films and adaptations, keeping Kipling's Indian jungle alive for new generations. Kipling wrote the tales while living in Vermont, drawing on his childhood in India for their setting.