1) The most-watched TV series finale in the United States was "MAS*H," with an estimated 105 million viewers.

2) The Grand Canyon, located in Arizona, United States, is a massive and awe-inspiring natural formation carved by the Colorado River. It is approximately 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and reaches a depth of over 1.8 kilometers (1.1 miles).

3) The world's largest flower is the Rafflesia arnoldii, which can grow up to 3 feet (1 meter) in diameter and weighs about 15 pounds (7 kilograms).

4) 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.