Answer:
For an organism to become a fossil, it must not decompose or be eaten. This can happen if the organism either lives within or is moved to a place where it can be buried and kept from decaying. When an organism is buried quickly, there is less decay and the better the chance for it to be preserved.
Explanation:
I copied and pasted from https://www.americangeosciences.org/education/k5geosource/activities/investigations/fossils/how-fossils-form ,it might help for your work.