1) 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.

2) The national flower of Japan is the cherry blossom, which holds great cultural significance and is celebrated during the annual cherry blossom festivals.

3) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

4) The word "bank" comes from the Italian word "banco," which means bench. In medieval Italy, bankers conducted their business on benches in the marketplace.