1) The process of photosynthesis, performed by plants, algae, and some bacteria, is responsible for producing the oxygen we breathe.

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

3) Democracy is a system of government in which power is vested in the people, who exercise it through elected representatives. It allows for political participation, freedom of speech, and protection of individual rights and liberties.

4) Banks play a vital role in the economy by facilitating the flow of funds between savers and borrowers, providing loans, and offering various financial services.