大学英语听说教程 第二册 unit1a

[18:02.15]A hundred strings might buy a canoe or a cow.
[18:07.24]Some people could eat their money!
[18:10.85]They made money out of salt,which they shaped into little bricks.
[18:16.65]The bricks were all of the same size and value.
[18:21.24]There was a picture of the king on each salt brick to show that the king would accept the salt as money.
[18:28.53]If the king would accept it, then everyone else would,too.
[18:33.73]Salt money wasn't heavy or awkward like stone money or so hard to find as shell money.
[18:41.02]But when it rained,the money might melt!
[18:45.22]Finally,people started using metal for money for example,copper and silver and gold.
[18:53.61]Metal wasn't easily damaged by water or heat or time.
[18:59.38]And since there wasn't very much of it,everyone wanted it.
[19:04.97]Metal money was certainly better than salt or shell or stone money.
[19:10.88]But if you have very much of it,metal money is hard to carry around.
[19:17.17]It's heavy and takes up a lot of space.
[19:21.77]So today we also have paper money,
[19:25.87]with numbers printed on it to show how much the money is worth.