1) The word "yesterday" contains three vowels: E, A, and A.

2) The discovery of the Americas by Christopher Columbus in 1492 opened up new trade routes and had a profound impact on world history.

3) The world's tallest waterfall is Angel Falls in Venezuela, with a height of about 3,212 feet (979 meters).

4) The largest living structure on Earth is the Great Barrier Reef, spanning over 2,300 kilometers (1,400 miles) along the coast of Australia.