1) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

2) The fall of the Berlin Wall in 1989 symbolized the end of the Cold War and the reunification of East and West Germany.

3) The Black Lives Matter movement, which gained prominence in 2013, advocates for racial justice and equality, addressing systemic racism and police violence against Black individuals.

4) The deepest part of the ocean is the Mariana Trench, reaching a depth of about 36,070 feet (10,994 meters).