What was the soviet union’s primary purpose in building the berlin wall?
a. to create a symbol of the boundary between eastern and western europe
b. to protect east germany from us attacks
c. to prevent east germans from escaping to west germany
d. to provide construction work to the laborers in east berlin

Your answer is C, they feared large amounts of people fleeing to West Berlin, and created the wall to control the population better.

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.