3. what can scientists learn from fossils found in rock layers?

Brief Explanations:

Fossils in rock layers can reveal information about past life - forms (species that existed), their evolution over time (through changes in fossil characteristics across layers), the environment in which they lived (such as climate and habitat based on the type of fossils and rock composition), and the geological history of the area (sequence of events like sedimentation and erosion).

Answer:

Scientists can learn about past life - forms, evolution, past environments, and geological history from fossils found in rock layers.