Beyond the answers - interesting background to this quiz

When television first linked two cities

The BBC's first television broadcast between London and Glasgow belongs to the 1920s, an era when television was still experimental and pictures travelled over telephone lines rather than satellites. John Logie Baird, a Scottish inventor, was central to these early demonstrations, showing that moving images could be sent between distant points. It was a far cry from today's live global coverage, but it proved the basic idea that television did not have to stay in one room.

The ocean that surrounds the pole

The Arctic Ocean is the smallest of the world's oceans, and also the shallowest. Much of its surface is covered by sea ice that shrinks in summer and grows again in winter, though the extent of that ice has been changing in recent decades. Unlike the other oceans, it sits almost entirely within the Arctic Circle, ringed by northern coasts of Europe, Asia and North America.

Persia, Iran and the names countries keep

Persia was the name used in the West for the country we now call Iran, and the change became official in 1935. The name "Iran" was not new - it derives from a word meaning "land of the Aryans" and had long been used by Iranians themselves. Similar stories exist elsewhere: Bohemia, a historical region of central Europe, is today part of the Czech Republic, which is why Czech is the language most associated with it.

A river that crosses a continent

The Danube flows through Austria, among many other countries, on a journey of roughly 2,850 kilometres from Germany's Black Forest to the Black Sea. It passes through or borders ten countries, more than any other river in the world, including Slovakia, Hungary, Serbia and Romania. Vienna, the Austrian capital, grew wealthy partly because it sat on this busy trade route.