What are the two most important assumptions in all of economics?

The two most important assumptions in all of economics is scarcity and cost

answer; john stuart mill's principle of utility is your answer; /// good luck

the first settlements began along the huang river because of the importance of the huang river in the beginning of china. it goes back to the story, “the tale of emperor yu”, which references the tale of the great flood, which was caused by the huang river and was believed to create and influence china’s making.