1) Cows have best friends and can become stressed if they are separated.

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

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 United Nations Security Council is responsible for maintaining international peace and security, with five permanent members (China, France, Russia, the United Kingdom, and the United States) holding veto power over resolutions.