Lesson47 The History of Money
Today, our currency is a mixture of coins and paper money, but it wasn't always that way. Before metal coins and paper bills existed, people used a lot of unusual things to buy what they needed. In one part of the world, for example, people used sharks' teeth for money. In some places, brightly collored feathers and rare seashells were money.
No one knows for sure when people started using metal coins for money. Archaeologists have found coins dating from 600 B.C., so we know they have been around for a long time. At first, people used precious metals, such as gold and silver, to make coins.
In the 1200s, people in China used iron coins for their currency. These coins weren't worth very much, so people had to use a lot of them to make their purchases. Because it was inconvenient to carry around a large number of heavy iron coins, the government started printing paper receipts. People took these receipts to banks and traded them in for coins.
This is the first example we have of paper money.
Today, most countries use a mixture of coins and paper bills for their currency. In the United States, the paper bills are all the same size and colour. For example, the one-dollar bill is the same size and colour as the one-hundred-dollar bill. In many other countries, the bills come in various sizes and colours. The smaller sized bills are worth less money. This makes it easier for people to tell the value of their money at a glance.

archaeologist 考古学家

货币的历史
今天，我们的货币包括硬币和纸币，但并不一直都是这样的。在金属硬币和纸币出现前，人们用许多稀奇的东西来购买他们需要的物品。例如，世界上有个地方的人用鲨鱼牙齿作货币。在有些地方，艳丽多彩的羽毛和罕见的贝壳被当做货币。
没人确切的知道人们从何时起开始使用金属硬币作为货币。考古学家称发现过可追溯到公元前600年的硬币，我们因此知道这些货币已经出现很长时间了。最初，人们用稀有金属，如金子和银子制造硬币。
公元1200年，中国人使用铁币作货币。这种硬币价值低，所以买东西时，人们不得不用很多货币。因为携带大量沉重的铁币出行不方便，政府开始印制纸质收据。人们带这些收据到银行，再把它们兑换成硬币。这就是最早的纸币。
当今，大多数国家使用硬币和纸币两种作为货币。美国纸币的尺寸和颜色都一样。例如，1美元纸币的大小和色彩与100美元的一模一样。在其他很多国家，纸币的尺寸和色彩很不一样。尺寸小一些的纸币，币值就小。这使人们一眼就能看出纸币的面额。