Answer:
Food Shortages - Moved to south
Too much or too little rain - built an irrigation system
Attacks by neighboring communities - built walls and moats
Irrigation system crossed village boundaries - worked together for the common good (keep water system moving)
Explanation:
1) Driven by the need for food, they searched elsewhere
2) They store that extra rain in an irrigation system to use for when there is little rain.
3) They defended themselves from neighboring communities attacking them by building walls and moats.
4) They kept the water system moving.
I would like to apologise in advance if any of these are incorrect.
