What are three ways carnegie, rockefeller and other corporate leaders consolidated control over their industries?

The ways that Carnegie, Rockefeller and other corporate leaders consolidated control over their industries is that they established a monopoly or trust, which centralized control of a number of oil-related companies under one board of trustees. As a result, they owned nearly the entire oil business in the United States, and could set prices at will. Companies in other industries quickly imitated their trust model and used their broad market control to push prices higher.

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.