How could shifts in the physical environment have caused major changes in early civilizations? Select all that apply.


A.Too much or too little rain may have ruined crops, creating food shortages.


A.Earthquakes or erupting volcanoes may have destroyed communities.


A.Buildup of silt could have made rivers less salty, increasing the supply of clean water.


A.Long-term farming could have improved the quality of the soil, increasing crop yields.