Rotation.
Crop rotation is when a farmer changes the crops grown in the same field each year to ensure he gets the best harvest possible by not exhausting the soil of specific nutrients by repeatedly growing the same thing.
Answer:
Eastern edge of Great wall was Pyongyang in North Korea in ancient, but Dandong is edge now
Explanation:
Aphrodite promised the mortal Paris, marriage to the most beautiful woman in the world, Helen, the wife of King Menelaus of Sparta, in exchange for a golden apple inscribe with the words "to the fairest".<span>
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The answer should be Duel federalism