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

2) In Norse mythology, Ragnarok is a cataclysmic event that signifies the end of the world. It involves a series of apocalyptic battles and natural disasters, leading to the destruction of the gods and the world as it is known. From the ashes, a new world and a new generation of gods emerge.

3) Insurance fraud occurs when individuals or organizations deliberately deceive insurance companies to receive undeserved benefits.

4) Mountains are important water sources, as they capture and store precipitation, feeding rivers and supporting ecosystems downstream.