1) The sunflower is not a single flower but a cluster of small flowers arranged in a spiral pattern.

2) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

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

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