[填空题]
The values in the economic system are measured in terms of
money.
Our goods and services are sold for{{U}} (31)
{{/U}}, and that money is in turn exchanged{{U}} (32) {{/U}}other
goods and services. Coins are adequate for small transactions,{{U}} (33)
{{/U}}paper notes are used for general business. There is additionally a
wider sense of the word "money", covering anything{{U}} (34) {{/U}}is
used as a means of exchange, whatever{{U}} (35) {{/U}}it may take.
Originally, a valuable metal (gold, silver or copper) served{{U}} (36)
{{/U}}a constant store of value, and even today the American{{U}}
(37) {{/U}}is technically "backed" by the store of gold which the US
government maintains. Because gold has been universally regarded as a very
valuable metal, national currencies were for many years judged in{{U}} (38)
{{/U}}of the so-called "gold standard". Nowadays, however, national
currencies are considered to be as strong as the na
