Задание: Change the sentences of the following text using infinitive complexes instead of subordinate clauses where possible.
Пример как должно выглядеть: EX. At the end of the 19th century, uranium compounds were investigated and it was found that they emitted penetrating rays. - At the end of the 19th century, uranium compounds were investigated and were found to emit penetrating rays.

ТЕКСТ:
At the end of the 19th century, uranium compounds were investigated and it was found that they emitted penetrating rays. It was discovered that these rays affected a protected photographic plate in much the same manner as X-rays. Besides, it was observed that these rays caused the air through which they pass to become a conductor of electricity. It was found that the rays from uranium compounds differed from X-rays, however, in that they were not produced by any artificial means. Instead, it appeared that they were emitted by certain materials quite spontaneously. It was proved that the production of these rays, therefore, was a perfectly natural process. Further work showed that a uranium mineral called “pitchblende” was much more strongly radioactive than could be accounted for by its content of uranium alone. It was, therefore, suspected that pitchblende contained some undiscovered element of greater radioactive power than uranium itself.
The research of the unknown element was undertaken by a Polish woman living in France, Maria Curie, who together with her husband, Pierre Curie, discovered the element she was searching for. The element was given the name “radium” and M. Curie stated that it resembled barium in being precipitable as an insoluble sulphate. By the analysis of radium chloride. M. Curie found that the atomic weight of radium was approximately 225 and later she obtained the more accurate value, 226.2, by analysing a relatively large quantity (0.1 g) of pure radium bromide.
Radium is interesting particularly because it emits rays which are similar to those first discovered in the case of uranium. This property has been named “radioactivity” and it was said that the substances that emit penetrating radiations were radioactive. The rays emitted possess energy as shown by their ability to affect the photographic plate, to cause zinc sulfide to emit light, and to render air a conductor of electricity. In addition, it may be shown that the emission of rays may be attended by a liberation of heat; it has been estimated that one gram of radium evolves as much as 133 calories of heat per hour. The evolution of heat does not depend on whether the radium is present as a chloride, a bromide, or in metallic form. This seems evident that the emission of heat is a property of the radium atom. Thus, it may be seen that radium atom is a source of energy that is released, in part, during the radioactive