1) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.

2) The painting "The Scream" by Edvard Munch is an iconic work of art that depicts a figure in anguish and has become a symbol of existential angst.

3) The United States operates under a two-party system, with the Democratic Party and the Republican Party being the two major political parties that compete in elections and shape the country's political landscape.

4) The speed of a sneeze can reach up to 100 miles per hour (160 kilometers per hour).