1) The word "oxygen" contains two vowels: O and E.

2) The FIFA Women's World Cup has been held since 1991 and showcases the best women's national soccer teams from around the globe.

3) The concept of 3D printing, also known as additive manufacturing, was first introduced in the 1980s and has since revolutionized prototyping and small-scale production.

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