精选优质文档-倾情为你奉上2014完型练习 (1) For many years the United States and the other countries used gold and silver as money. Paper money was used to stand for the holdings(储备)of both gold and silver. The value of silver was limited to that of gold. Fifteen ounces(盎司)of silver had the same value of one ounce of gold. These values did not change until after 1860 when mines(银矿)in the west of the United States began to 80 large amounts of silver. This extra amount of silver caused the price of si
