Here's an example. Let's say I'm interested in Ancient Roman aqueducts.
- I might have a question: "where is the source of the water for the aqueducts that fed water to Rome?"
- While I'm getting the answer to that question, I might ask "How did they build the aqueducts?"
- Which might lead to the question "How did they get through the hills and valleys?"
- Which might lead to the question "How does water pressure work?"
- A final question might be "Where else do we use water pressure in modern times?"