The introduction of refrigerated railroad cars benefited u. s. residents by:

it is a better alternative

swahili is an extremely rich and complex civilization, a set of ethnic groups articulated by a language and a series of cultural elements that fuse the african traditions, islam and indian culture. this growth was largely a result of the indian ocean trading network that brought in not just man-made riches, but also religious ideas, specifically islam, which had a significant impact on the local culture. furthermore, the development of the swahili language gave a common cultural unity to the people.

d

explanation:

it establishes america’s basic laws and fundamentals to its citizens.