1) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

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

3) The national animal of Australia is the kangaroo.

4) The Dow Jones Industrial Average (DJIA) is a stock market index that tracks the performance of 30 large, publicly owned companies in the United States.