1) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

2) The corpse flower, or titan arum, is known for its unpleasant smell, often compared to that of rotting flesh.

3) The Cuban Missile Crisis in 1962 brought the United States and the Soviet Union to the brink of nuclear war during the Cold War.

4) The term "bull market" refers to a period of rising stock prices, while a "bear market" refers to a period of falling stock prices.