The Indus River is the correct answer.
The event or incident that triggered long standing tensions in Europe and was the immediate cause of ww1 was the assasination of archduke Ferdinard and his wife sophie, in sarajavo by a Bosnian student.
<span>The one topical reason for the plague portrayed by ibn khaldun which visited eurasia between the time period of 1331 and 1347 is that the rats, bugs, microbes, military clash in Caffa, as well as financial exchange or economic trade interfaces between Afro-Eurasia.
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