What is a consequence of following the comparative advantage principle? a. countries only make one kind of good or service. b. wages scale to exactly match the skill of the wage-earners. c. countries become more interdependent on one another for goods and materials. d. goods are traded directly, rather than using monetary trade.

Plastic and steel are substitutes in the production of body panels for certain automobiles. if the price of plastic increases, with other things remaining the same, we would expect: a) the demand curve for plastic to shift to the left. b) the price of steel to fall. c) the demand curve for steel to shift to the left d) nothing to happen to steel because it is only a substitute for plastic. e) the demand curve for steel to shift to the right