1) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

2) The Paralympic Games, held immediately after the Olympic Games, showcase the athletic abilities of individuals with disabilities and promote inclusivity in sports.

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

4) Elvis Presley, often referred to as the "King of Rock and Roll," has sold over one billion records worldwide.