请阅读 Passage 2，完成第 26~30小题 。Passage 2Paper money is used ever

请阅读 Passage 2，完成第 26~30小题 。Passage 2Paper money is used every day but people do not often think of money as just paper.This is because people agree that it has value，and paper money is supported by the government.People have used paper money for only a few hundred years，but what did people do before printed money was invented? In Medieval England，a stick was the official representation of money. The common system that was used involved counting debt on a piece of wood called a "tally stick". The tally stick was marked with a knife.Each mark，or tally，indicated an amount of money.The tally stick acted as a contract.No one really knows who invented the tally stick，but King Henry I of England is credited as the first to use the stick in a widespread fashion.In England，the tally stick was used from 1100-1826.Marks were made on a tally stick to represent the amount of service or goods that were exchanged.The tally stick was cut in halflengthwise into two parts，and one stick was longer than the other.The person giving services or goods received the longer end of the stick，called the "stock"，and the person paying for the service or goods received the shorter end.Once the stick was cut，it could not be altered.When put together，the two halves fit perfectly together.Medieval England was not the only country to use the tally stick system.In 1960，Belgian scientist Jean de Heinzelin de Braucourt discovered an extremely old tally stick made of baboon bone in Africa.At first，he determined the stick to be between about 8，000 to 10，000 years old.This surprised many people because it proved that the tally stick system had been in use for much longer than everyone had previously thought.Further research has shown that this stick is actually much older: now，scientists believe it is 20，000 years old.The tally stick system may no longer be in use today，but its influence is still apparent.People still make contracts and people still borrow and lend money.People still trust that "things"-whether they are sticks，paper，or coins-have value.The next time paper money is used，just remember: it is only paper!Why were many people surprised about tihe tally stick in Africa?