每年春天，河边的低洼地都会被洪水淹没，但土壤非常肥沃。

Every spring, the ___bottomland by the river gets flooded, but the soil is extremely fertile.

农场位于河谷的洼地，那里土壤肥沃适合种植。

The farm is located in the ___bottomland of the river valley, where the soil is fertile for crops.