Answer:
The greatest achievement of Roman civilization was the domination of the Mediterranean Sea.
Step-by-step explanation:
The dominance of the Mediterranean Sea allowed the Roman civilization to increase its slave structure, which stimulated the workforce to produce products that would be easily marketed. This commercialization was also stimulated by the dominance of the Mediterranean Sea because it allowed the Romans no impediment to expand their commercial horizons. In addition, they would find it easy to expand the Roman Empire, since this expansion was done mainly by marine means.