What religion were the saracens likely to practice

Islam

Explanation:

The Saracens were what Christian writers durning the time refered to Muslims. Muslims practice the religion of Islam an Abrahamic monotheistic religion teaching that Muhammad is a messenger of God.

these civilizations were located around fertile rivers, where they could produce an abundance of crops

most people now work in jobs where they do one  kind  of work; they are carpenters, bankers, cooks, mechanics, and so forth. likewise, most  businesses produce  only certainkinds  of  goods  or  services, such as cars, tacos, or gardening  services. this feature of  production  is known as specialization.