III. Choose the right form of the Participle.

1. Many buildings from the 18th and 19th centuries are still (standing; stood) in Odessa.

2. In Ukraine people's deputies are (electing/elected) for a term of four years.

3. In some areas, too much (untreating/untreated) sewage is pumped out and the water in rivers never gets clean.

4. The (rushing/rushed) water drives the turbines.

5. The large amounts of oxygen (requiring/required) for industry are produced in a different way.

6. The (defining/defined) property of gases is their ability to expand indefinitely.

7. While (working/worked) to separate polonium, the Curies discovered a second radioactive element "radium".

8. (Having put/having been put) into an orbit the satellite took its way to Mars.

9. Temperature is usually (expressing, expressed) in degrees Centigrade (°C) or Fahrenheit (°F).

10.Artificial cold (using, used) in our everyday life became an integral part of modern civilization.

11.The (fixing, fixed) points on which the Centigrade scale is (basing, based) are the melting point of ice (0°C) and the boiling point of water at atmospheric pressure (100°C).

12.Thermocouples are (using, used) to measure very high temperatures.

13.When (cooling, cooled) water becomes ice.

14.The (using, used) temperature varied from 90 to 100 degrees.

15.The (improving, improved) methods of work brought good results.

IV. Review of tenses. Write the correct verb forms.

1.The electronic system ... the reliability and ... the accuracy in the control of compressor capacity, (to increase,to improve)

2. The demand for maximum reliability ... the installation of large numbers of screw compressors in modern vessels throughout the world. (to result in)

3. In refrigeration the word evaporation ... the process of liquid boiling. to mean)

4. Fluids used for generating cold are termed refrigerants. A number of substances ... in this capacity. (to use).

5. How long ... you ... English? (to learn)

6. I ... to write to my parents yesterday. (not manage)

7. It … certainly ... hot this summer! (to be)

8. "How is your new car?" "Everything ... all right up to now". to be)

9. The possibility of employing inexpensive readily available refrigerants ... very important for economical operation. (to be)

10. When I... in this street, this house ... (to live, to build)

11. The material ... before it ... in the construction (to test: to use)

12. My parents ... here for 30 years. (to work)

13. When they came to the USA, they found that the language was quite different from the English that they ... in their country (to learn).

14. What are you doing? — I (to watch) TV.

15. Artificial cold ... many commercial applications (to have)

16. This unit of heat ... the kilogram-calorie (to call)