"To be" and its functions. "To have" and its functions

7. Modal Verbs
I. Translate the following sentences. Pay attention to the modal verbs:

1. Heat is a form of energy and may be measured in the units which energy is measured. 2. We must say that the discovery of energy is as important as the discovery of fire. 3. Electronic machines can add, subtract, multiply and divide much quicker than man 4. The origin of automation can be traced back to the early days of the industrial revolution. 5. She may use different methods in her research work. 6. For a long time scientists could not discover the secret of atom. 7. This equipment can work with high accuracy. 8 You may use these devices in your research work. 9. The atom is a great force that must be used for the good of mankind. 10, Chemists must create the materials which don't exist in nature. 11. Naturally, this circuit can be modified if necessary. 12. This kind of energy must find application in transport.

II. Choose the sentences where the verbs to have and to be are used in the functions of modal verbs and translate them:

1. These devices have been used in our experiment. 2. Scientists have to work hard to create a new atomic technique. 3. A modern computer has two main parts: a memory and a computing unit. 4. As the known resources of coal and oil are limited, man has to find new sources of power. 5. Very difficult calculations in mathematics and elect­rical engineering have to be solved by computers. 6. People of good will have to struggle for peaceful use of atomic energy. 7. We are to take into consideration all the advantages and disadvantages of this device for the future work. 8. We are to take special steps to reduce the weight of this mechanical part. 9. These new data are obtained after our experiment. 10. At present our engineers are to develop the most advanced methods of production. 11. Our design bureau has to construct a new adding machine. 12. This device has been used in our experiment. 13. The experts are to inspect this plant.