6. Найдите предложения, в которых сказуемое используется в пассивном залоге. Выпишите такие сказуемые. Напишите их форму (время и залог).
Money is any object or record that is generally accepted as payment for goods and services and repayment of debts in a given country or socio-economic context. The exchange of goods and services in markets is among the most universal activities of human life. To facilitate these exchanges, people settle on something that will serve as a medium of exchange—they select something to be money.
However, this has not always been true. In primitive societies a system of barter was used. Barter was a system of direct exchange of goods. Somebody could exchange a sheep, for example, for anything in the market place that they considered to be of equal value. Barter, however, was a very unsatisfactory system because people’s precise needs seldom coincided. People needed a more practical system of exchange, and various money systems developed based on goods which the members of a society recognized as having value. Cattle, grain, teeth, shells, feather, salt, tobacco have been used. Precious metals gradually took over because, when made into coins, they were portable, durable, recognizable and divisible into larger and smaller units of value.
The main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, occasionally in the past, a standard of deferred payment. When money is used to intermediate the exchange of goods and services, it is performing a function as a medium of exchange. It thereby avoids the inefficiencies of a barter system, such as the ‘double coincidence of wants’ problem.
Money also serves as a unit of account. A unit of account is a standard numerical unit of measurement of the market value of goods, services, and other transactions. Also known as a “measure” or “standard” of relative worth and deferred payment, a unit of account is a necessary prerequisite for the formulation of commercial agreements that involve debt.
The third function of money is to serve as a store of value, that is, an item that holds value over time. To act as a store of value, money must be able to be reliably saved, stored, and retrieved – and be predictably usable as a medium of exchange when it is retrieved. The value of the money must also remain stable over time. Money, of course, is not the only thing that stores value. Houses, office buildings, land, works of art, and many other commodities are regarded as a means of storing wealth and value. Money differs from these other stores of value as it is readily exchangeable for other commodities. Its role as a medium of exchange makes it a convenient store of value.
Because money acts as a store of value, it can be used as a standard for future payments. When you borrow money, for example, you typically sign a contract pledging to make a series of future payments to settle the debt. These payments will be made using money, because money acts as a store of value.
The money supply of a country consists of currency (banknotes and coins) and usually includes bank money (the balance held in checking accounts and savings accounts). Bank money, which consists only of records (mostly computerized in modern banking), forms by far the largest part of broad money in developed countries.

Money is any object or record that is generally accepted as payment for goods and services and repayment of debts in a given country or socio-economic context. is accepted as payment - present simple, passive voiceHowever, this has not always been true.has not been true - present perfect, passive voiceIn primitive societies a system of barter was used. was used - past simple, passive voiceCattle, grain, teeth, shells, feather, salt, tobacco have been used.have been used - present perfect, passive voiceThe main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, occasionally in the past, a standard of deferred payment. are distinguished as - present simple, passive voiceWhen money is used to intermediate the exchange of goods and services, it is performing a function as a medium of exchange. is used to - present simple, passive voiceTo act as a store of value, money must be able to be reliably saved, stored, and retrieved – and be predictably usable as a medium of exchange when it is retrieved. is retrieved - present simple, passive voiceHouses, office buildings, land, works of art, and many other commodities are regarded as a means of storing wealth and value. are regarded - present simple, passive voiceThese payments will be made using money, because money acts as a store of value.will be made - future simple, passive voice