- A wooded area is a kind of place
- If fossils of a water animal or plant are found in a place then that place used to be covered by water in the past
- Fossils of seashells are found in a wooded area
- So, the wooded area used to be covered by water in the past

- The wooded area used to be covered by water in the past
- If something used to be in the past then that something has changed
- Therefore, the place has changed from being covered by water to a wooded area

So, the place has changed from being covered by water to a wooded area
Question
Which would best aid a scientist in discovering how Earth may have changed over time?

Context
- A wooded area is a kind of place 
- If fossils of a water animal or plant are found in a place then that place used to be covered by water in the past 
- If something used to be in the past then that something has changed 
- Fossils of seashells are found in a wooded area