Please answer the question below
20 POINTS

How did the technology of the late 1800s affect the growth of cities? select one: a. cities were able to expand outward because of additions to railroads. b. electric streetcars enabled the wealthy city dwellers to move to the first suburbs. c. advances in steel and metal technology allowed for the development of the skyscraper, which allowed cities to grow upwards. d. all of these are correct.

Before the civil war, the constitution protected slavery -true -false

Those who resisted the mongol invaders were attacked and their towns burned; those who cooperated with them also were attacked and had their towns burned. were treated fairly. were taken into the tribes and treated as mongols. were sent away to find new homes.