An encyclopedia is a reference book that contains information about persons, places, events, and things it is concerned with who, what, where how, and why of the things. It is widely used in research because it provides more detailed and technical information on specific areas of knowledge, such as art, medicine, or the social sciences.

below are topics to research on. choose one and refer to an encyclopedia for brief information.
1. Why earthquakes occur
2. How man makes rain
3. how gold is formed

pick on from the 3 give the topic also with your answer.