1) Oceans play a crucial role in regulating the Earth's climate by absorbing and storing large amounts of heat and carbon dioxide.

2) Cristiano Ronaldo is a Portuguese professional soccer player widely regarded as one of the greatest footballers of all time. He has won numerous awards, including multiple FIFA Ballon d'Or titles, and has played for top clubs such as Manchester United, Real Madrid, and Juventus.

3) Antarctica is the coldest, driest, and windiest continent on Earth. It is also the highest, with an average elevation of about 7,545 feet (2,300 meters).

4) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.