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

2) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active.

3) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

4) The word "pizza" contains two vowels: I and A.