Suppose russia produces only tablets and smartphones. the resources that are used in the production of these two goods are not specialized—that is, the same set of resources is equally useful in producing both smartphones and tablets. the shape of russia's production possibilities frontier (ppf) should reflect the fact that as russia produces more smartphones and fewer tablets, the opportunity cost of producing each additional smartphone

Juanita and sam attend a beach party and notice that the local beach appears to have a great deal more trash washed up on shore than it did when they were young. the water doesn't appear nearly as clear, and there seems to be less evidence of small water creatures living in the shallows. an afternoon at the local library convinces them that one major cause is the new factory nearby. after some discussion, they decide their next step should be identifying the cause of the changes identifying the problem picketing the guilty factory lobbying their elected representatives to complain about the problem talking to a local environmental group about solutions