1) The process of impeachment involves charging a public official, such as a president or high-ranking government official, with misconduct and potentially removing them from office through a trial and vote by the legislature.

2) The first successful human heart transplant was performed by Dr. Christiaan Barnard in 1967.

3) The world's largest ocean, the Pacific Ocean, covers an area of approximately 63 million square miles.

4) The highest mountain in Africa is Mount Kilimanjaro, standing at 19,341 feet (5,895 meters) tall.