1) 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.

2) The abolition of slavery in the United States was officially proclaimed with the ratification of the 13th Amendment to the Constitution in 1865.

3) The first sound film, "The Jazz Singer," was released in 1927 and marked the transition from silent movies to "talkies."

4) The Indian Ocean is the third-largest ocean and is characterized by its warm waters and diverse marine life.