What are the two biggest reasons that Rome was in the center of the Empire?

Constantinople was the largest and richest urban center in the Eastern Mediterranean Sea during the late Eastern Roman Empire, mostly as a result of its strategic position commanding the trade routes between the Aegean Sea and the Black Sea. It would remain the capital of the eastern, Greek-speaking empire for over a thousand years.

20000 pounds

Explanation:

Generally 1 gallon of fuel burnt gives of 20 pounds of CO₂

Difference in the gallons of fuel burnt

The 20 mpg car burns 1000 gallons of fuel more than the 30 mpg car

The amount of CO₂ would be

The fewer pounds that the 30 mpg car would release is 20000 pounds