1) The ocean covers about 71% of the Earth's surface and contains roughly 97% of the planet's water.

2) The first successful human heart transplant was performed by Dr. Christiaan Barnard in 1967.

3) Elvis Presley, often referred to as the "King of Rock and Roll," has sold over one billion records worldwide.

4) The concept of self-driving cars, or autonomous vehicles, is being actively developed by companies such as Tesla, Google (Waymo), and Uber.