In an ecosystem, what do organisms and populations with similar needs compete over?

Look at the map of cities in the united states at the turn of the twentish century what impact did railroads have on cities across the united states at the turn of the twentish century

In the wake of the civil war, compared to the south the north had sustained very little destruction. had to create a new labor system. had more economic challenges. had to repair damaged property.

In article v of the united states constitution, the amendment process is explained. why did the framers include provisions for amending the constitution? a) to limit the individual liberties of american citizens b) to allow the constitution to adapt to future circumstances c) to allow the president to change the constitution as needed eliminate d) to ensure that state governments had more power than the nation