1. For the first question, the correct response is **irrigation systems**. Irrigation systems are essential for farmers in areas that experience drought, as they provide a way to supply water to crops when natural rainfall is insufficient.
2. For the second question regarding Sub-Saharan Africa, the best description of the relationship between poor soil and deforestation is: **Poor soil quality is a result of deforestation, as the removal of trees leads to increased erosion and nutrient loss, negatively impacting agricultural productivity.** This highlights the cyclical nature of soil degradation and deforestation, where each exacerbates the other.