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

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

3) Mount Everest, located in the Himalayas, is the highest peak on Earth, with an elevation of 8,848 meters (29,029 feet). It is a popular destination for mountaineers and represents a significant challenge due to its extreme altitude and harsh weather conditions.

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