Beyond the answers - interesting background to this quiz

The lake that sits inside a volcano

Crater Lake, in the US state of Oregon, fills the caldera left behind when Mount Mazama collapsed after a major eruption. With no rivers flowing in or out, it is fed almost entirely by rain and snow, which helps give it its famous deep blue colour. It is the deepest lake in the United States and the deepest in North America. Its depth is often cited as close to 600 metres.

A crab that can crack a coconut

The coconut crab is the largest land-living arthropod in the world, a group that includes insects, spiders and crustaceans. It can grow a leg span of around a metre and weigh several kilograms. Despite the name, it is an opportunistic feeder rather than a coconut specialist, eating fruit, seeds and carrion. It is found on islands across the Indian and Pacific Oceans.

Hemingway and a generation in Paris

Ernest Hemingway's "The Sun Also Rises", published in 1926, follows a group of expatriates travelling from Paris to the Running of the Bulls in Pamplona, Spain. The novel is closely tied to the so-called Lost Generation, the writers and artists who came of age around the First World War. Its spare, direct prose style became hugely influential on later fiction.

Dumas, a novelist who worked with a collaborator

Alexandre Dumas wrote "The Count of Monte Cristo", a sweeping adventure of betrayal and revenge published in the 1840s. He was enormously productive, and much of his work was produced with assistants and collaborators, most notably Auguste Maquet. Dumas also wrote "The Three Musketeers", so both titles in this quiz belong to him.

Newton and the story of the apple

Isaac Newton set out his law of universal gravitation in his major work, the "Principia", published in 1687. The well-known story of an apple falling and prompting his thinking is often told, though it has been embellished over the centuries. What matters scientifically is that Newton proposed that the same force pulling objects to the ground also keeps the Moon in orbit around the Earth.