Much of the wealth of the west african kingdoms of ghana and mali was gained from a. controlled the trade routes across the saharab . develop self-sufficient economiesc. became religious center considered scared to africansd. receive support from european colonial government

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.

is there a year set? the question is incomplete