Question

what did the nile leave behind when it flooded? loess sand rich soil large rocks

Explanation:

The Nile River floods annually. When it floods, it deposits sediment. This sediment is rich in nutrients and forms fertile soil. Loess is a type of wind - blown sediment. Sand is a common sediment but not as nutrient - rich as the soil left by the Nile. Large rocks are not typically deposited by a river flood in the context of the Nile's floodplain.

Answer:

rich soil