2.Choose the right translation of the infinitive. Pay attention to its tense form.

1. The investigation is expected to be completed before the summer vacation

а) будет завершено, б)завершается, в) завершено

2. Our computing center is reported to have solved a number of problems for our economy

а) решает, б) решил, в) будет решать

3. Pyotr Kapitsa was the first to discover super fluidity

а) открывает, б) будет открывать, в) открыл

4. We shall be the first (the last) to write, the written test.

а) пишем, б) писали, в) будем писать

5. They are unlikely to change their plans.

а) изменяют, б) изменили, в) изменят

6. The idea of space flights is known to have attracted the attention of people since the remotest times.

а) привлекает, б) привлекала, в) будет привлекать

7. Не is sure to take part in our discussion.

а) припишет, б) принял, в) примет

8. The construction of the new plant is likely to be completed ahead of time.

а) завершается, б) было завершено, в) будет завершено

9. The lаsеr beam is assumed to have almost unlimited industrial possibilities.

а) имеет, б) имел, в) будет иметь

10. Many new materials are reported to have been scientists by our scientists.

а) синтезируются, б) были синтезирована, в) будут синтезированы

3 Translate into Russian paying attention to the subjective infinitive construction:

1. Radium is known to be very radioactive.

2. For a long time the atom was thought to be indivisible.

3. Electrons are known to revolve around the nucleus along closed orbits.

4. Their number is known to be equal to that of the protons in the nucleus of the atom. 5. Uranium is known to give off alpha, beta and gamma rays.

6. New types of reactors are reported to have been designed.

7. All nuclei are now believed to be built up from two types of fundamental particles. 8. The problem whether the atom can or cannot be split up is known to have interested scientists from ancient times.

9. If the forces have no tendency to increase or decrease the displacement, the body is considered to be in equilibrium.

10. The atomic weights of over 600 isotopes are known to have been measured with great accuracy.

11. The atomic weights of the light isotopes are known to have been measured with particularly high absolute accuracy.

12. Beryllium is found to have four electrons.

13. All metals are known to consist of minute particles called molecules.

14. A new atomic station is supposed to be built next year.

15. These particles are termed neutrons and have been shown by disintegration experiments to be constituents of all nuclei.

16. The nucleus is now considered to consist of Z protons together with (A—Z) neutrons, where Z is the atomic number and A is the atomic weight.

17. No electrons are considered to be present in the nucleus, but the positive or negative particles emitted in the corresponding radioactive changes are considered to be created by the spontaneous transition of a proton into a neutron or a neutron into a proton.

18. By carrying out experiments similar to those devised to establish the nature of electrons, β-rays may be shown to be electrons moving with velocities which vary over an enormous range both with different elements and for any one element.

19. All the electrons are assumed to be identical.