usd是什么货币？

　　usd是英文United States dollar的缩写，代表美元的意思，又称美圆、美金，作为美国的官方货币。它的出现是由于《1792年铸币法案》的通过。它同时也作为储备货币在美国以外的国家广泛使用。当前美元的发行是由美国联邦储备系统控制。最常用的表示美元的符号是“$”，而用来表示美分的标志是“？”。国际标准化组织为美元取的ISO 4217标准代号为USD。

Wed is an abbreviation of the English United States dollar, which represents the dollar, also known as the dollar, as the official currency of the United States. It emerged as a result of the passage of the Casted Currency Act of 1792. It is also widely used as a reserve currency in countries other than the United States. The current distribution of the dollar is controlled by the United States Federal Reserve system. The most commonly used symbol for the dollar is “ $&rdqua; and the symbol used to indicate the United States dollar is & &ldquao; &rdquao; and the ISO 4217 standard code for the dollar, adopted by the International Organization for Standardization (ISO) for the dollar, is USD.

　　美元纸币正面主景图案为人物头像，主色调为黑色。背面主景图案为建筑，主色调为绿色，但不同版别的颜色少有差异，如1934年版背面为深绿色，1950年版背面为草绿色，1963年版背面均为墨绿色。上面的签名是财政部长的签名，不同发行年代是不同的财政部长。

The headline of the front of the dollar banknotes is a figure with the main color in black. The backside is a building with the main color in green, but there are few variations in different colours, such as the late 1934 editions, the late 1950 editions, the green of grass, and the back of the 1963 editions, all ink green. The signatures are signed by the Minister of Finance, who was different in the years of issuance.