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

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

3) The ocean is home to an incredible variety of marine life, including thousands of species of fish, mammals, reptiles, and invertebrates.

4) The world's largest desert is the Antarctic Desert, covering around 5.5 million square miles.