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

2) The highest mountain in Africa is Mount Kilimanjaro, standing at 19,341 feet (5,895 meters) tall.

3) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

4) The painting "The Scream" by Edvard Munch is an iconic work of art that depicts a figure in anguish and has become a symbol of existential angst.