Final answer:
The Roman Empire depended heavily on slavery and forced labor for economic productivity, military conquest and expansion for acquiring resources, and on agriculture and food production to sustain its population. Additionally, trade with other civilizations was vital for spreading Roman goods and importing luxuries.
Step-by-step explanation:
As the Roman Empire expanded, it became increasingly reliant on several key elements. One of the most significant dependencies was slavery and forced labor. Slaves were primarily war captives but could also be individuals born into slavery or those who were kidnapped or abandoned as infants. This system of slavery was critical to the Roman economy, as it underpinned a variety of industries and contributed to the wealth of the society.
The empire was also heavily dependent on military conquest and expansion. Periods of conquest allowed Rome to control resources, attain wealth, and expand their territory. This not only bolstered the economy but also helped to feed the populace and pay the troops. The military played an integral role in economic control, with new territories often contributing resources to the Roman economy.
Agriculture and food production were also crucial to the empire's growth, as witnessed by the strategic acquisition of regions like Egypt, Sicily, and Sardinia that were significant grain-producing territories. Finally, trade with other civilizations facilitated the influx of luxury goods and spread Roman merchandise across the Mediterranean. This interconnectivity via trade routes was essential for the function of the expansive Roman economy.