•poll taxes
• literacy tests
• threatened violence
the measures in the list above all existed in southern states in order to undermine the content of
a the 15th amendment.
b the emancipation proclamation.
c the 13th amendment.
d the gettysburg address.

Poll taxes, literacy tests and threatened violence were all measures that existed in Southern states in order to undermine the content of A) the 15th Amendment. This was due to the South having a hard time coming to terms with the fact that they were obligated to give African-Americans equal voting rights. The above were both harsha and offensive tactics used against former slaves, so that they were unable to vote.

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.