The earth is unitedddddddddddddddddddddddddddddddddddddddddddddddddddddddddd
B. the transfer of energy from one organism to another
Depending on how early you are speaking of, but generally females were required to stay home and raise their children while males often went to work or war. If war, females usually found jobs as well to support their families whilst their spouse was away.
D) the law of increasing costs.
The brainpop video is: https://www.brainpop.com/socialstudies/elections/parliamentarysystem/
