Cuneiform was the written system of the c)Sumerians. Cuneiform is one of the earliest systems of writing and is generally "written" in a wedge-shaped style. It took many years for people to translate these texts and it is known that these were lists people kept to keep track of their domesticated animals in their agricultural territory.
I think there are a lot. But I am not a genius
It is hard to say without looking at your source (textbook or article if you have one associated with this question) but in the most recent studies, it has been Islam.
