1) The invention of the printing press by Johannes Gutenberg in the 15th century revolutionized the spread of knowledge and played a key role in the Renaissance.

2) The Triple Crown in horse racing consists of three prestigious races: the Kentucky Derby, the Preakness Stakes, and the Belmont Stakes.

3) The Earth's core is hotter than the surface of the Sun.

4) The concept of sovereignty refers to the supreme authority and power of a state to govern itself, make decisions, and control its own territory without interference from external forces.