1) The Mongol Empire, under the leadership of Genghis Khan, became the largest contiguous empire in history, spanning from Asia to Europe.

2) Cyclones play a vital role in Earth's climate system by redistributing heat and moisture, maintaining global temperature patterns, and influencing weather patterns.

3) Bats are the only mammals capable of sustained flight.

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