A butterfly flaps its wings and brings down a dead leaf, and a story unfolds
He and she were originally people on two different parallel lines. They lived unrelated things. One lived in the countryside and was a child of the mountains. The other lived in the city and was a product of the times. If it hadn't been for some chance coincidences that caused the two parallel lines to intersect, they might never have met in their lives.
Purpose: Understand the difference between rural and urban areas