1) The Amazon rainforest produces more than 20% of the world's oxygen.

2) The first smartphone, the IBM Simon, was introduced in 1992 and featured a touchscreen, email capabilities, and apps such as a calendar and calculator.

3) The NBA (National Basketball Association) is widely regarded as one of the most popular and competitive professional basketball leagues in the world.

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.