Which definition is better in economic and why

Which factor best suggests a cause for the urban problems shown in this table? (3 points) increasing discriminatory housing practices shifting population density gradients over time declining urban renewal efforts by city governments declining basic employment sector in industrial cities increasing gentrification efforts in the inner cities

Why are nation-states difficult to create?

When top-roping is used, how long should the rope be in order to protect the climber throughout the climb?