1) The United States recently held its presidential election in 2020, resulting in Joe Biden being elected as the 46th President of the United States and Kamala Harris as the Vice President, making history as the first female Vice President.

2) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.

3) The Mona Lisa, painted by Leonardo da Vinci, is one of the most famous and valuable artworks in the world.

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