Beyond the answers - interesting background to this quiz

When a king really was a king

Elvis Presley's rise to fame in the 1950s coincided with a cultural shift in the United States, as rock and roll brought together influences from blues, country and gospel music. His early recordings for Sun Records in Memphis, Tennessee, and later his national television appearances, made him one of the most recognizable performers of the decade. The nickname "King of Rock and Roll" stuck because, for many listeners, he came to represent the genre itself.

A river that crosses borders

The Amazon is the largest river in the world by volume of water, and it does not stay in one country. It begins in the Andes mountains of Peru and flows eastward across Brazil before emptying into the Atlantic Ocean. Along the way it also touches Colombia, and its vast drainage basin extends into several other South American nations, including Suriname, which shares a border with Brazil and forms part of the wider Amazon region.

A revolution that came in two waves

The Russian Revolution is usually dated to 1917, the year the tsarist autocracy collapsed and the Bolsheviks took power under Vladimir Lenin. But there was an earlier upheaval in 1905, when protests and strikes forced Tsar Nicholas II to make concessions, including the creation of a parliament, the Duma. That first revolution did not topple the regime, but it set the stage for the events that followed more than a decade later.

Two cities, one capital

Bolivia is one of the few countries in the world with more than one capital city. Sucre is the constitutional and judicial capital, while La Paz serves as the seat of government, where the president and legislature operate. This arrangement dates back to the nineteenth century, when the country's leadership moved to La Paz for practical and political reasons, leaving Sucre with its formal constitutional status.

The many names of methane

Methane is the simplest hydrocarbon, made of one carbon atom and four hydrogen atoms, which gives it the formula CH4. It is the main component of natural gas and is also produced by livestock, wetlands and landfills. Though it does not stay in the atmosphere as long as carbon dioxide, it traps heat far more effectively, which is why it is a major focus in discussions about climate change.