All scientific models, including economic models, simplify reality in order to improve our understanding of it

Suppose the United States is experiencing a balance of payments surplus. To prevent the exchange rate from appreciating, the U.S. Treasury must

A) sell dollars and buy foreign currency. B) sell both dollars and foreign currency. C) buy both dollars and foreign currency. D) sell foreign currency and buy dollars.

Over a given period, economic depreciation is the change in capital equipment's

A) output. B) market value. C) rate of return. D) cost of maintenance.