Beyond the answers - interesting background to this quiz

A river that belongs to six nations

The Mekong is one of Asia's great waterways, rising on the Tibetan Plateau and running through China, Myanmar, Laos, Thailand, Cambodia and Vietnam before emptying into the South China Sea. Its lower basin supports one of the world's most productive freshwater fisheries, and millions of people depend on it for food and irrigation. Because it crosses so many borders, managing the river is an international effort as much as an environmental one.

Why mercury is Hg

Several chemical symbols come from Latin names rather than English ones, which is why they can look puzzling at first glance. Mercury's symbol, Hg, derives from hydrargyrum, a Latin term built from the Greek words for "water" and "silver" - a fitting description of the only metal that is liquid at room temperature. Barium follows a similar logic: its symbol, Ba, comes from the Greek barys, meaning "heavy".

Jane Austen's quiet radicalism

Jane Austen published Emma in 1815, the same year as the Battle of Waterloo, though her novels rarely mention the great events of her era. Instead she worked on a small canvas: courtship, inheritance, manners and the subtle power of money. Emma Woodhouse, "handsome, clever, and rich", was a heroine Austen suspected nobody but herself would much like - a risky choice that produced one of English literature's most enduring novels.

Paella and the art of the Spanish coast

Paella originated in Valencia, on Spain's eastern coast, where rice has been grown for centuries. The traditional version is cooked outdoors over an open fire in a wide, shallow pan - the paella itself - and is associated with rice, saffron, vegetables and, in its best-known form, seafood or rabbit and chicken. It is now one of Spain's most internationally recognised dishes, though Valencians are famously particular about what belongs in it.