Beyond the answers - interesting background to this quiz

A speech that still echoes

Martin Luther King Jr. delivered "I Have a Dream" in 1963 from the steps of the Lincoln Memorial in Washington, D.C., during the March on Washington for Jobs and Freedom. Speaking to a crowd of more than 200,000 people, he called for an end to racial discrimination and for equality. The phrase "I have a dream" was partly improvised after the gospel singer Mahalia Jackson urged him to tell the crowd about his dream. The speech is now regarded as one of the most important in American history.

The element named after a laboratory

Livermorium takes its name from Lawrence Livermore National Laboratory in California, where researchers collaborated on its discovery. Its chemical symbol is Lv, and it carries the atomic number 116. Like many of the heaviest elements, it does not occur in nature and can only be produced in a laboratory, where it decays within moments. It was officially named in 2012.

Wine, words and ancient Greece

An oenophile is a lover or connoisseur of wine. The word comes from the Greek "oinos", meaning wine, and "philos", meaning loving or dear. English has borrowed several wine-related terms from Greek, including oenology, the study of winemaking. So the next time someone swirls a glass and talks about tannins, you will know exactly what to call them.

The pull of the tides

Tidal power harnesses the rise and fall of the sea to generate electricity, and South Korea leads the world in installed capacity. Its Sihwa Lake Tidal Power Station, opened in 2011, is one of the largest of its kind. Unlike wind or solar, tidal energy is highly predictable, since tides follow the moon's cycle. France and the United Kingdom also operate notable tidal schemes, but South Korea's output remains the benchmark.

Cape Verde's Atlantic capital

Praia, the capital of Cape Verde, sits on the southern coast of Santiago Island. The name means "beach" in Portuguese, reflecting the country's colonial history. Cape Verde is an archipelago of ten volcanic islands in the Atlantic Ocean, roughly 570 kilometres off the coast of West Africa. Praia became the capital in 1770, replacing the older settlement of Ribeira Grande.