Answer:
1. Sharecropping is a legal arrangement about agricultural land in which a landowner allows a tenant to use the land in return for a share of the crops produced on that land.
3. a. due largely to land degradation, such as erosion, which is when soil components move from one location to another by wind or water.
b. Agricultural land is also being lost because it is being converted for other purposes, such as highways, housing and factories.
c. land pollution including industrial waste and quarrying of stone, sand and minerals.
d. inappropriate irrigation.
4. For, 70 years — 100 years.
7. Tribal territories and the slave trade ranged over present-day borders. Some Native American tribes held war captives as slaves before and during European colonization. Some Native Americans were captured and sold by others into slavery to Europeans, while others were captured and sold by Europeans themselves.