Explain one cause for low agricultural productivity in Africa and a possible solution.

Explain why components that are naturally found in air can be considered air pollutants.

Explore the ways that boundaries influence identity, interaction and exchange. things to consider: what is the race/ethnicity. how easy is it to interact/trade with others.

Sandstones that form in aeolian (wind/desert) environments appear very different from other sandstones, such as those formed in a beach/ shoreline environment and in rivers on land. give three identifying properties for each of the three sandstones that would tell a geologist which depositional environment they formed in. consider things such as the relationship between transportation and grain size, shape, roundness, sorting, fossils and composition.