17. How did the innovations of the industrial revolution have a social impact on society? 18. What are contributing factors that led to the establishment of the plantation system in America?

19. What contributed most to the rapid industrialization of the United States in the years before the civil war?

20. What allowed the United States to become a top producer of steel?

21. What was the most significant result of the construction of the Erie Canal?

22. What region of the U. S. was most densely populated during the industrial revolution?

23. What region was the least densely populated?

The constant presence of diseases or infectious agents within a given geographic area or population group. it may also refer to the usual prevalence of a given disease with such area or group. it includes holoendemic and hyperendemic diseases. a holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). a hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. so probably family history.