the answer would actually be C. the decline of the Roman Empire -> the emergence of the feudal system -> the Crusades -> the emergence of towns and a middle class. Its C
Answer:
The Little Rock Nine were a group of nine black students who enrolled at formerly all-white Central High School in Little Rock, Arkansas, in September 1957. Board of Education, a landmark 1954 Supreme Court ruling that declared segregation in public schools unconstitutional
Explanation:
Positive effect is the usage of more land whereas negative effects is the control problem of that land.
<h3>Effects of settling the west</h3>
The positive effect of settling the west is that it provides America more land to use and its resources for the betterment of the economy while on the other hand, the negative effect of setting the west is that it was more land to control for the United States as well as the United States had to fight 2 wars to gain the territory.
<h3>Effects of railroads on the physical environment</h3>
The main disturbances caused by railways are air, soil and water pollution and noise which adversely affect species and organisms present in that environment.
Learn more about railroads here: brainly.com/question/2724028
