Answer:
In telling these two stories, Park illustrates the history of the Sudan, as well as its more current difficulties. Salva left the Sudan amidst war and death. He struggled to make his way out of the country and persevered to meet his goal..... he never gave up. This history stayed with Salva, and his experiences left him wanting to do more. His experiences were the reason he began the organization, Water for Sudan.
Explanation
Nya's story is an extension of Salva's. She epitomizes the difficulties the persist with the country. The life she leads illustrates how many things have not changed, and will never change without outside help. When Salva returns to the Sudan, he changes her life, as well as the lives of the many people who suffer from a lack of fresh water. Salva's purpose becomes Nya's salvation.
