30. Put the verbs in brackets into the correct tense.

1. We had studied the properties of this material before we began to use it.

2. Temperature changes affecting nearly all properties of matter.

3. Pierre and Marie Curie discovered radium in 1898.

4. Electromagnetic waves travel with the velocity of light.

5. Here you are at last! I have been looking for you.

6. We shall start our experiment next week if everything goes on well.

7. Do you realize what you have said?

8. For four years this expert has been working (has worked) at his subject.

9. Changes continually are taking place in the properties of bodies around us.

10. His family was staying in the village while Nick was taking his exams.

11. Note the direction in which the conductor is moving in the magnetic field at this moment.

12. How long have you been studying (have you studied) at the university?

13. By the end of the week we will have spent all our money. But by that time I hope, I will have found a job.

14. My watch stopped as I hadn`t wound it up.

15. Have you read anything about nuclear physics?

16. They have tested the new device this week. The test was successful.

17. When night came some of physicists stopped their research in the laboratory, but the others still were continuing working over the experiments.

18. He published the results of his working out that he had been carrying out for many years.

19. When we arrived at the university, the classes had not begun yet. The students were hurrying to take their places, when the professor came in.

31. Fill in the gaps with

1. A suitable preposition and translate the following sentences into Ukrainian.

1. The physicists of (in) the future will have to repeat the experiments of the past.

2. Roentgen published photos of the bones of his hand and (of) keys photographed through the pocketbook.

3. Pitchblende is the ore from which uranium is obtained.

4. “Polonium” was called in honour of M.Curie’s native Poland.

5. Polonium wasn’t rich enough in the rays to be the end of the search.

6. In 1898, the search came to a conclusion.

7. Those were exciting days in the field of physics.

B. a suitable preposition from the list.

from, on, to (2), in (2), before, by (2), of (6), according to

"The interest of research workers has frequently been focused 1) on the phenomenon 2) of regularly shaped crystals suddenly forming 3) from a liquid, e.g. a supersaturated salt solution. 4) According to the atomic theory the forming force 5) in this process is to a certain extent the symmetry characteristic 6) of the solution 7) to Schrödinger's wave equation, and to that extent crystallization is explained 8) by the atomic theory. Nevertheless this process retains a statistical and − one might almost say − historical element which cannot be further reduced:even when the state 9) of the liquid is completely known 10) before crystallization, the shape 11) of the crystal is not determined 12) by the laws 13) of quantum mechanics. The formation 14) of regular shapes is just far more probable than that of a shapeless lump. But the ultimate shape owes its genesis partly 15) to an element of chance which 16) in principle cannot be analysed further." Werner Heisenberg