1) In recent years, climate change has become a significant global concern, leading to increased efforts to reduce carbon emissions, promote renewable energy, and implement sustainability measures.

2) The novel "To Kill a Mockingbird" by Harper Lee has been translated into more than 40 languages and has sold over 40 million copies worldwide.

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

4) The concept of 3D printing, also known as additive manufacturing, was first introduced in the 1980s and has since revolutionized prototyping and small-scale production.