Which of the main architectural building materials allowed for theconstruction of taller buildings with thinner walls than before, despite its disadvantage of being heavy?
A- wood
B- stone
C- cast iron
D- concrete
E- steel

1. what was the result of growing nationalism and pan-africanism on european-african relations? africans were encouraged to seek independence from europe. european colonialism grew and strengthened in africa. the change of power from european to african rule went smoothly. africans believed they could live peacefully with europeans.