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

2) Serena Williams, an American tennis player, has won a total of 23 Grand Slam singles titles, making her one of the most successful players in the history of the sport.

3) Beyoncé, full name Beyoncé Giselle Knowles-Carter, is a highly influential American singer, songwriter, actress, and businesswoman. She rose to fame as a member of the group Destiny's Child and has since achieved success as a solo artist.

4) Sourdough bread is a type of bread made through a fermentation process that involves wild yeast and lactic acid bacteria. It has a distinct tangy flavor and a chewy texture. Sourdough bread is often considered healthier than conventional bread due to its potential benefits for digestion and nutrient absorption. It has gained popularity in recent years, with artisanal bakeries and home bakers reviving the traditional art of sourdough baking.