1-C. The Mesopotamian year was divided into 360 days, so the base-60 system fit very well into their calendar.The Mesopotamian year was divided into 360 days, so the base-60 system fit very well into their calendar.
2-C. Ancient Mesopotamians believed the base-60 system was unusual.Ancient Mesopotamians believed the base-60 system was unusual.
古代のメソポタミア人は、信じていた、60進法が普通でなかった(時制の一致)とダヨ。
3-C. Ancient Mesopotamians, whose system of time we have adopted, are believed to have used a base-60 system.Ancient Mesopotamians, whose system of time we have adopted, are believed to have used a base-60 system.