The Mpemba effect It is named after Erasto Mpemba, who discovered the phenomenon in 1963 while in Form 3 of Magamba Secondary School, Tanzania.
What city has more than one hundred kilometres of canals (the main ones called Herengracht, Prinsengracht, and Keizersgracht), which were dug in the 17th century to form concentric belts around the city, known as the grachtengordel?
What is the term used to describe the collection of flowers in species that have more than one flower on an axis (sometimes called "composite flowers"?
