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

2) Cows have best friends and can become stressed if they are separated.

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 Treaty of Tordesillas, signed in 1494, divided the newly discovered lands outside of Europe between Spain and Portugal, leading to the colonization of the Americas.