1) The study of fossils is called paleontology, and it helps us understand the history of life on Earth and the process of evolution.

2) 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.

3) The tongue of a blue whale is so big that about 50 people could stand on it.

4) The International Monetary Fund (IMF) and the World Bank are international financial institutions that work to promote global financial stability and economic development.