Answer: I would say region
Explanation: The definition for region is an area having definable characteristics but not always fixed boundaries.
It is called a Building: Because the suffix 'ing' is added to verbs to make noun forms. For instance a celebrity's following. Following describes the people who follow them in a noun form.Building is a noun form of a thing that exists as the result of the act of those who built it.
Answer: A) switch from crops to livestock.
Hope this helps, sorry if I got this wrong.
Answer:
B. During warmer climates, glaciers melt and sea level rises.