Beyond the answers - interesting background to this quiz

A symphony written on American soil

Antonín Dvořák composed his Ninth Symphony, "From the New World", during his years as director of the National Conservatory of Music in New York in the early 1890s. He was fascinated by African American spirituals and Native American melodies, and he believed American composers should build a national style from those sources rather than from European models. The symphony's famous "Going Home" theme from the second movement was later fitted with words and became a popular song in its own right.

The reef that is alive and visible from space

The Great Barrier Reef is not a single organism but a vast network of coral colonies built over thousands of years by tiny animals called polyps. It stretches for more than 2,000 kilometres off the coast of Queensland, Australia, and is often described as the largest structure made by living creatures. Corals are sensitive to warming water, which makes the reef one of the most closely watched ecosystems on the planet.

Carlo Pedersoli, the athlete who became Bud Spencer

Before he was Bud Spencer, Carlo Pedersoli was a successful swimmer: he represented Italy at the Olympics and was the first Italian to swim the 100 metres freestyle in under a minute. He later moved into acting, and his on-screen partnership with Terence Hill produced a string of popular comedies, including the Piedone films. The pair's playful brawls and slow-motion fistfights became their trademark.

Burning hydrogen and the case for clean fuel

When hydrogen burns in the presence of oxygen, the main product is water, which is why it is often discussed as a low-carbon fuel. In practice, most hydrogen today is produced from natural gas, so its environmental benefits depend heavily on how it is made. The element is also the most abundant in the universe and fuels the reactions inside stars.

Beriberi and the discovery of vitamins

Beriberi, a disease affecting the nerves and heart, results from a lack of vitamin B1, also called thiamine. It was once common in parts of Asia where people ate heavily polished white rice, which strips away much of the grain's thiamine. The search for its cause helped establish the very idea of vitamins: essential nutrients the body needs in small amounts but cannot make itself.