In which century did the United States of America begin using decimalised currency?
1900s | 1600s | 1800s | 1700s
Who was the French physicist who, in 1852, invented the gyroscope?
Gabriel Lippmann | Louis de Broglie | Léon Foucault | Henri Becquerel
What was John Tradescant one of the first to collect specimens of in the early 17th century?
Plants | Birds | Fossils | Insects