1) The first commercial mobile phone, the Motorola DynaTAC 8000X, was released in 1983 and weighed nearly 2 pounds.

2) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

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) Dwayne "The Rock" Johnson is an American actor, producer, and former professional wrestler. He has become one of the highest-paid actors in Hollywood, known for his roles in films such as the "Fast & Furious" franchise, "Jumanji," and "Moana."