1) Orchids are one of the largest families of flowering plants, with over 25,000 species.

2) The word "bank" comes from the Italian word "banco," which means bench. In medieval Italy, bankers conducted their business on benches in the marketplace.

3) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

4) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.