Вставьте правильный глагол: must или have to

MONEY IS USED FOR BUYING OR SELLING GOODS, FOR MEASURING VALUE AND FOR STORING WEALTH.Almost every society now has a money economy based on coins and paper notes of one kind or another. 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 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 a value. Cattle, grain, teeth, shells, features, skulls, salt, elephant tusks and tobacco have all 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. A coin is a piece of metal, usually disc-shaped, which bears lettering, designs or numbers showing its value. Until the 18th and 19th centuries coins were given monetary worth based on the exact amount of metal contained in them, but most modern coins are based on face value, the value the governments choose to give them, irrespective of the actual metal content. Coins have been made of gold, silver, copper, aluminum, nickel, lead, zinc, plastic and in China even from pressed tealeaves. Most governments now issue paper money in the form of notes, which are “promises to pay". Paper money is obviously easier to handle and much more convenient in the modern world. Checks, bankers, cards and credit cards are being used increasingly and it is possibly to imagine a world where “money” in the form of coins and paper currently will no longer be used.

1. You ... come in when you have taken off your boots. 2. Be careful: you ... spill the milk if you carry it like that. 3. Most children ... slide on the ice very well. 4. I don't think I ... be here by eleven o'clock tomorrow, but I ... be. 5. ... you see anything in this inky darkness? 6. You ... go when you have finished your compositions. 7. What shall we do if the train is late? It ... be late, you know, after the terrible snowstorms we've had. 8. When ... you come arid see me? — Let me see: I ... not come tomorrow, for I must be at the meeting, but on Sunday I'll find time. Yes, you ... expect me on Sunday about three o'clock. Will that be all right?
Упр. 470. Вставьте модальные глаголы may (might) или can (could).
1. ... I use your pen? 2. ... I find a pen on that table? 3. You ... read this book: you know the language well enough. 4. You ... take this book: I don't need it. 5. ... I help you? 6. ... I ask you to help me? 7. ... you help me? 8. I ... not imagine her speaking in public: I knew that she was so shy. 9. Something was wrong with the car: he ... not start it. 10. A fool ... ask more questions than a wise man ... answer. 11. She asked me if she ... use my telephone. 12. The school was silent: nothing ... be heard in the long dark corridors. 13. Waiting ... be endless, you know. 14. ... you tell me the nearest way to the city museum? 15. They ... think that I am too weak to take part in the excursion, but I am strong enough to do any kind of hard work, indeed. 16. He knew this period of history very well: he had read everything on the subject he ... find in the rich university library.