Final answer:
Greek fire was the technological advantage that enabled the Byzantines to stop Arab attacks in the eighth century.
Step-by-step explanation:
The technological advantage that enabled the Byzantines to stop Arab attacks in the eighth century was Greek fire. Greek fire was a highly flammable substance made from naphtha that the Byzantines used to set enemy ships alight. It made them a formidable force on the seas and helped them defend against Arab attacks.
In addition to this, the exact composition of Greek fire was a closely guarded secret, but it is believed to have contained a mixture of substances such as petroleum, sulfur, and quicklime. The Byzantines developed a specialized delivery system that allowed them to project Greek fire onto enemy ships from tubes mounted on their vessels. This technological advantage gave the Byzantines a significant edge in their defense and contributed to their success in repelling Arab invasions.