1) The word "country" contains three vowels: O, U, and Y.

2) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

3) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

4) The world's first paper money was created in China over 1,000 years ago.