1) The impact of social media platforms on society and politics has been a subject of debate, including concerns about misinformation, privacy, online harassment, and the influence of these platforms on public opinion and democratic processes.

2) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

3) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active. It stands over 13,000 feet (4,000 meters) above sea level.

4) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.