Beyond the answers - interesting background to this quiz

The rainforest that spills across nine borders

The Amazon is often pictured as a single, vast wilderness, but it is shared. Around 60 percent of the rainforest lies within Brazil, with significant portions in Peru and Colombia, and smaller areas in Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. That makes it less a national landmark and more a cross-border ecosystem, which is one reason international cooperation matters so much to its future.

A play that became a musical phenomenon

George Bernard Shaw's Pygmalion premiered in 1913, retelling the ancient myth of a sculptor who falls for his own creation. Shaw used the story to poke at class and language, making speech itself the measure of social mobility. Decades later, the musical My Fair Lady adapted his play, and the transformation of Eliza Doolittle became one of the stage's most enduring roles.

Coral reefs and the question of scale

Australia's Great Barrier Reef is the largest living structure on Earth, stretching over 2,000 kilometres off the Queensland coast. It is not a single reef but a network of thousands of individual reefs and islands, home to an enormous range of marine species. Coral reefs worldwide, however, are under pressure from warming waters and other environmental changes.

The tiny state between two neighbours

Andorra sits high in the Pyrenees, wedged between Spain and France, and is one of Europe's smallest countries. Its official language is Catalan, a reminder of its cultural ties to the region rather than to either of its larger neighbours. The country is perhaps best known today for its ski resorts and its status as a tax haven.

A vitamin with many jobs

Vitamin B6 is a family of related compounds that the body uses in over a hundred enzyme reactions, many of them involved in breaking down proteins. It also plays a role in producing neurotransmitters, which is why a deficiency can affect mood and nerve function. Good sources include poultry, fish, potatoes and bananas.