67. The law of increasing opportunity costs exists because: A) wage increase economies approach full employment. B) resources are not equally efficient in producing different goods. C) inflation leads to a decrease in purchasing power over time. D) producers are likely to overcharge consumers when there are shortages. E)the additional output generated by workers decreases over time.

68. A significant improvement in technology will: A) shift the PPC from PP1 to PP2. B) shift the PPC from PP2 to PP1. C) move the economy from A to C along PP1. D) move the economy from A, B, or C on PP1 to D. E)cannot be shown on this graph

69. The concept of opportunity cost is best represented by the: A) shift of the PPC from PP1 to PP2. B) move from B on PP1 to E on PP2. C) move from B on PP1 to C on PP1. D) move from D inside PP1 to B on PP1. E) cannot be shown on this graph