1) The first modern health insurance policy was introduced in Germany in the late 19th century.

2) 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.

3) The United States recently held its presidential election in 2020, resulting in Joe Biden being elected as the 46th President of the United States and Kamala Harris as the Vice President, making history as the first female Vice President.

4) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.