In ancient times wealth was measured and exchanged in things that could be touched: food ,

tools, and previous metals and stones. Then the barter system was replaced by coins, which still had real value since they were pieces of rare metal. Coins were followed by fiat money, paper notes that have value only because everyone agrees to accept them.

Today electronic monetary systems are gradually being introduced that will transform. money into even less tangible forms,reducing it to a series of "bits and bytes" ,or units of computerized information, going between machines at the speed of light.

Already, electronic fund transfer allows money to be instantly sent and received by different banks, companies, and countries through computers and telecommunications devices.

1、According to the passage, which of the following was the earliest kind of exchange of wealth？

A.Bartered goods.

B.Fiat money

C.Coin currency

D.Intangible forms

Which of the following statements about computerized monetary systems is NOT supported by the passage？A.They promote international trade.

B.The allow very rapid money transfers.

C.They are still limited to small transactions

D.They are dependent on good telecommunications systems.

The author mentions food,tools and precious metals and stones together because they are all__________.A.useful items

B.articles of value

C.difficult things to obtain

D.material objects

According to the passage, coins once had real value currency because they__________.A.represented a great improvement over barter

B.permitted easy transportation of wealth

C.were made of precious metals

D.could become collector's items

请帮忙给出每个问题的正确答案和分析，谢谢！