1) The English alphabet has five vowels: A, E, I, O, and U.

2) The fingerprints of koalas are so similar to humans that they have been mistaken at crime scenes.

3) The world's largest flower is the Rafflesia arnoldii, which can grow up to 3 feet (1 meter) in diameter and weighs about 15 pounds (7 kilograms).

4) The Industrial Revolution led to significant urbanization, as people migrated from rural areas to cities in search of employment in factories.