D. <span>Its people have rebelled against communism.</span>
Answer:
Fleeing crop failure, land and job shortages, rising taxes, and famine, many came to the U. S. because it was perceived as the land of economic opportunity. Others came seeking personal freedom or relief from political and religious persecution.
Explanation:
loc.gov
I don’t really know but Friction and Hydraulics are a principle but I feel like it’s O:)