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

III. Translate the sentences. Pay attention to the use of modal verbs and their equivalents:

1.Without a computer scientists will not be able to solve complicated problems. 2.Modern computers can multiply two numbers in a microsecond. 3. This machine can do the work of hundreds of workers. 3. He has to finish his experiment in time. 4. She was allowed to carry out this research as she had taken part in the scientific symposium. 5. Every student must know the difference between automation and mechanization. 6. With the help of radioactive elements we were able to measure the thickness of various materials. 7. Every engineer must improve his technical knowledge. 8. Scientists of different count­ries must cooperate in their research and peaceful application of their discoveries. 9. In fact, there is hardly any sphere of life where the atom may not find useful application. 10. The computer can perform different mathematical operations. 11. Our plant is to increase its output. 12. Every plant must fulfill its plan in time. 13. Workers must apply new methods of production.

IV. Translate the following sentences paying attention to modal verbs with Perfect Infinitive:
1. Why have you made this mistake? You must have known the rule. 2. Dr. Smith hasn’t arrived yet. He must have missed his bus. 3. I could have gone to the conference, but I lost my invitation. 4. You might have made the experiment more carefully. 5. The explosion must have occurred long ago. 6. No living being could have survived in such a climate. 7. Some problems of science could not have been solved without isotopes. 8. The engineer might have overlooked something that may turn out to be important in carrying out this experiment. 9. All the preparations must have been completed long ago. 10. He may have got the condenser he needed for his experiment. 11. He cannot have broken the tube while making this experiment. 12. You should have changed the current strength at all points of the circuit. 13. He may have got the article he needed. 14. You should have helped your friend. 15. It is believed that these rocks could not have been more than 5 000 years old. 16. Life may have existed on that planet.