<span>o,t,t,f,f,s,S,E,N,T,E,T </span> <span>It's the first letter of all the numbers starting with one, two, three, four,... </span>
<span>The second pattern I might guess would be move the O back two spaces then move one space back, then repeat. </span> <span>JKLMNO, JKLOMN, JKOLMN, OJKLMN, JKLMON, JKOLMN, ... </span> <span>The second one I'm not sure about because there are only three starting terms to work with. It's hard to see the real pattern with that little to work with. </span>
Answer: They led to larger urban cores that used professional armies to increase their territory and enslave people.
Explanation:
Trade routes to West Africa before European colonization was led by Muslim traders who came and converted people to Islam whilst trading.
This trade created large urban areas that grew so rich from trade that they were able to command and maintain larger armies which they used to increase their territories and conquer neighbouring lands and enslave their people. This was how the Songhai and Mali empires became so powerful.