1) The process of photosynthesis, performed by plants, algae, and some bacteria, is responsible for producing the oxygen we breathe.

2) The #MeToo movement, originating in 2006 and gaining widespread attention in 2017, raised awareness about sexual harassment and assault, encouraging survivors to share their experiences and promoting discussions on consent and gender equality.

3) The Industrial Revolution led to significant urbanization, as people migrated from rural areas to cities in search of employment in factories.

4) The recent advancements in space exploration include missions to Mars by various space agencies, such as NASA's Perseverance rover landing on Mars in 2021, aiming to explore the planet's geology and search for signs of past microbial life.