1) The largest living structure on Earth is the Great Barrier Reef, spanning over 2,300 kilometers (1,400 miles) along the coast of Australia.

2) The word "music" contains two vowels: U and I.

3) The fastest land animal is the cheetah, capable of reaching speeds up to 70 miles per hour (113 kilometers per hour) in short bursts.

4) The world's first credit card was introduced in 1950 by Diners Club.