Choose all that apply. What are four reasons for the fall of the Indus Valley civilizations?

earthquakes and tectonic uplifts
decreases in trade
emigration to other countries to get jobs
recurring floods
Aryan invasions
lack of natural resources
Chinese invasions

What was one important characteristic of the russian military during world war i? a. it had more advanced military technology than its western european allies. b. it was an all-volunteer military that enjoyed high morale throughout the war. c. it defended russian territory but refused to attack german positions d. it was unable to provide its forces with adequate weapons and supplies.