1) Emma Watson is a British actress and activist known for her role as Hermione Granger in the "Harry Potter" film series. She has since starred in films such as "The Perks of Being a Wallflower" and has been actively involved in promoting gender equality and women's rights.

2) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.

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

4) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active.