Which statement best describes a negative effect of human activity on Africa’s waterways? A. Dams have changed river flows, which has led to erosion.
B. The use of rivers to water crops has led to droughts.
C> Population growth has led to the destruction of rivers.
D The use of river transportation has harmed water quality.

A)Dams have changed river flows, which has led to erosion.

Explanation:

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.

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