Which of these is the major cause for the fall of the persian empire?

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.

What groups are bryan drawing a contrast between ? check all that apply a. people in the city and people in the country b. people who are educated and people who are not c. people who are in favor of free silver and people who want the gold standard d. people who work and people who don't

How did the us change it’s economy to provide supplies for the war effort?