Someday in the future we may not need to have money in our pockets. Is life easier when people don't need to carry any money at all? Is money heavy to carry? Is it safe to carry money? Maybe in the future each of us will have only one small credit card(信用卡). We will use it instead of money to buy all the things.
Of course we may still have some of the same problems with cards as we now have with money. For example, we lose money from time to time. Maybe we still lose the cards. Maybe someone will take the cards. Someone may even make a card that looks like our cards. Since we can't buy anything without our cards, the credit cards may be no better than money.
Is there something easier to use than credit card? Each of us has a thumbprint(拇指指纹). No two thumbprints are the same. Maybe someday the government will keep people's thumbprints with a number. When you want to buy something, you will put your thumb on a machine or a computer. Each store or business willpossessone. Everyone's thumbprint will be in the computer. It will be difficult to lose our thumbprints! It will be difficult for someone to steal it or to make one like it.