Section BDirections: There are 2 passages in this section. Each passage is followed by som

Section B

Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.

Resources can be said to be scarce in both an absolute and relative sense: the surface of the Earth is finite, imposing absolute scarcity; but the scarcity that concerns economists is the relative scarcity of resources in different uses. Materials used for one purpose cannot at the same time be used for other purposes; if the quantity of an input is limited, the increased use of it in one manufacturing process must cause it to become

less available for other uses.

The cost of a product in terms of money may not measure its true cost to society. The true cost of, say, the construction of a supersonic jet is the value of the schools and refrigerators that will never be built as a result. Every act of production uses up some of society's available resources; it means the foregoing of an opportunity to produce something else. In deciding how to use resources most effectively to satisfy the wants of the community, this opportunity cost must ultimately be taken into account.

In a market economy the price of a good and the quantity supplied depend on the cost of making it, and that cost, ultimately, is the cost of not making other goods. The market mechanism enforces this relationship. The cost of, say, a pair of shoes is the price of the leather, the labor, the fuel, and other elements used up in producing them. But the price of these inputs, in turn, depends on what they can produce elsewhere--if the leather can be used to produce handbags that are valued highly by consumers, the prices of leather will be bid up correspondingly.

What does this passage mainly discuss？

A．The scarcity of manufactured goods.

B．The value of scarce materials.

C．The manufacturing of scarce goods.

D．The cost of producing shoes.