Answer:
B) fertile farmland supported crop production
Explanation:
The Roman population grew quickly, thanks to surplus production of grains, olives and other crops.
The main way in which "new scientific discoveries between the 15th and 18th centuries contributed to the Enlightenment" was that "<span>D. They showed the reason could provide better answers about the world than tradition or religion."</span>
Answer:
It probably hasn't happened because the theory behind Marxism is wrong. A government can't control the economy efficiently enough for it ever to work well enough for communism to be practical. That's why there are almost no communist countries left today.