Final answer:
The ancient Babylonians had a good understanding of the cycles of the moon and used illustrations to demonstrate its phases.
Step-by-step explanation:
The ancient Babylonians had a keen interest in the cycles of the moon and made significant observations and recordings about it. They were aware of the different phases of the moon and how it changed in appearance throughout the month. To demonstrate this, they used illustrations and diagrams to depict the various stages of the moon's cycle. For example, they would draw a crescent shape to represent a waxing or waning moon and a full circle to symbolize a full moon.