Beyond the answers - interesting background to this quiz

A river that crosses six countries

The Mekong begins on the Tibetan Plateau and runs roughly 4,900 kilometres to the South China Sea, passing through China, Myanmar, Laos, Thailand, Cambodia and Vietnam. In Laos and Cambodia it supports huge freshwater fisheries, and its seasonal flood pulse drives agriculture along the banks. Dams upstream, especially in China, have changed how much sediment and water reaches the lower basin.

A belt of dry land south of the Sahara

The Sahel is a semi-arid strip stretching across Africa, from the Atlantic coast to the Red Sea. Chad sits within it, and so do countries such as Niger, Mali and Sudan. Rainfall there is low and highly variable, which makes farming and herding precarious. Droughts in the 1970s and 1980s brought the region to global attention and shaped later debates about desertification.

Two German states become one

German reunification took effect on 3 October 1990, when the German Democratic Republic joined the Federal Republic of Germany. The Berlin Wall had already fallen in November 1989, opening the way for rapid political change. The date is now marked as German Unity Day, the country's national holiday.

Dante and the making of Italian

Dante Alighieri wrote the Divine Comedy in the early 14th century in a form of Tuscan Italian rather than Latin. That choice helped establish the vernacular as a serious literary language. He spent his final years in exile from Florence, and the city later tried, unsuccessfully, to recover his remains.

Handel's Messiah and its charity premiere

George Frideric Handel composed Messiah in 1741, and it was first performed in Dublin in 1742 as a charity concert. The composer, born in Germany, spent most of his career in London. The work's "Hallelujah" chorus became so popular that audiences traditionally stand during it, a custom often traced to King George II.