1) The Great Barrier Reef in Australia is the largest coral reef system in the world and is visible from space.

2) The Russian Revolution in 1917 resulted in the overthrow of the monarchy and the establishment of a communist government under Vladimir Lenin.

3) Taylor Swift is an American singer-songwriter known for her narrative songwriting, catchy pop tunes, and successful albums such as "Fearless," "1989," and "folklore." She has won numerous awards, including Grammy Awards, and has a dedicated fan base worldwide.

4) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.