Hlp ? !

1. which geographic feature limited the expansion of west africa civilizations?
a. drakensberg mountains
b. great rift valley
c. nile river
d. sahara desert

2. how did camels increase trade across geographic barriers of northern africa?
a. they pulled loaded carts much faster then horses did.
b. they needed little sleep and rarely became ill.
c. they carried heavier loads and traveled far without water.
d. they traveled at night more easily then most other animals.

3. how did arab muslims primarily interact with east african city states?
a. through conquest
b. through pilgrimage
c. through scholarship
d. through trade

1. the answer is C
2. the answer is C
3. the answer is D
3=d

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.