One of the positive impacts the Columbian Exchange had on the world, was the massive exchange of crops. With the new crops brought into the Old World, the population increased due to the fact that the new crops were easy to store, grew fast, could withstand droughts well, gave a very high yield in calories. (at least 100 words needed)

It has become an important food in Europe, Egypt, India, China, and other countries. Cattle were brought to Mexico in 1521. They became an important source of food and can pull and lift heavy loads. Horses allowed hunters to travel great distances and increased the area over which natives could search for food.

Explanation:

imperial crisis leads to civil war.

roman forces withdraw from britain as goths attack rome.

odoacer topples romulus augustus

huns attack the empire and drive german peoples ahead of them.

elastic potential energy