If you choose between two summer jobs, what is the one you do not choose called?
question 3 options:

trade-off

opportunity cost

decision at the margin

opportunity at the margin

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel