1) The game of baseball, often referred to as "America's pastime," is played between two teams of nine players and has a rich history dating back to the 18th century.

2) The Russian Revolution in 1917 resulted in the overthrow of the monarchy and the establishment of a communist government under Vladimir Lenin.

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

4) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.