Oracle bones are bits of animal bone or turtle shell that tell historians a great deal about ancient china. which of the following best describes the significance of oracle bones?
a. they were used as a protection against evil spirits in folk traditions.
b. they represented the earliest known writing from ancient china.
c. they depicted the ancient chinese tendency to worship animals.
d. they told the story of the development of agriculture in china.

From what I know from the Shang Dynasty I would have to say B.

most of the oracle bones were carved with writings and then heated to the point they would crack. Then someone would interpret what the cracks meant.

Hope this helps answering your question 

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.