1) Lightning strikes the Earth about 8 million times a day.

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 Renaissance period, which began in Italy in the 14th century, marked a renewed interest in art, literature, science, and philosophy.

4) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.