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

2) The Sahara Desert, located in North Africa, is the largest hot desert in the world, covering an area of about 9.2 million square kilometers (3.6 million square miles). It is characterized by vast stretches of sand dunes, rocky plateaus, and extreme temperatures.

3) The ancient Egyptian civilization, with its impressive pyramids, pharaohs, and hieroglyphics, flourished along the Nile River for thousands of years.

4) The highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.