Beyond the answers - interesting background to this quiz

Two rivers, one ancient land

The Tigris and the Euphrates both run through Iraq, and together they defined Mesopotamia, the "land between the rivers" where some of the world's earliest cities and writing systems emerged. The Tigris rises in the mountains of eastern Turkey and flows south-east for roughly 1,850 kilometres before joining the Euphrates and emptying into the Persian Gulf. Because it carries more water than its sister river and floods quickly, its banks have supported irrigation farming for thousands of years.

An element hiding behind a vitamin name

Calciferol and niacin are both names we meet in nutrition - forms of vitamin D and vitamin B3 respectively - which is exactly why caesium, a soft, silvery-gold alkali metal, is the odd one out. Caesium sits near the bottom of the periodic table and is famous for its extremely accurate atomic clocks, the kind that underpin global timekeeping. Its name comes from the Latin caesius, referring to the blue lines in its spectrum.

The southern capital

Of Tbilisi, Manila and Tashkent, Manila lies closest to the equator, at around 14 degrees north, while Tbilisi sits at about 41 degrees north and Tashkent at roughly 41 as well. That latitude helps explain the Philippine capital's tropical climate, with a hot, humid wet season and a slightly cooler dry season. It is also one of the most densely populated cities in the world.

Dickens and the serial novel

Oliver Twist first appeared in 1838, but not as a finished book: it was published in monthly instalments in Bentley's Miscellany, with the young author also serving as the magazine's editor. Serial publication shaped how Victorian readers experienced fiction - they followed plots month by month, discussed them, and waited for the next cliffhanger. The novel's portrait of workhouses and child poverty made it one of Dickens's most enduring works.

A composer, a filmmaker and their crafts

Gustav Holst completed The Planets between 1914 and 1916, writing a suite of seven movements, each named for a planet and its astrological character rather than its astronomy. Decades later, Francis Ford Coppola directed The Godfather, released in 1972 and adapted from Mario Puzo's novel. Both works show how a single strong concept - the character of a planet, the arc of a family - can carry an entire artistic structure.