How did most of the americans who lived between the appalachians and the mississippi river make a living?
a) they were farmers
b) they were sailors
c) they were dock workers
d) they worked in factories

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.