One evening Mr. Cavor invited me to see his work and l went to his house. It was large and simply furnished. Mr. Cavor had no servants, there were only his three assistants who helped him in his work. But all the intellectual work was done by Mr. Cavor. The object of Mr. Cavor's research was a substance that had to be «opaque» to all forms of radiant energy. “Radiant energy”, he told me “is something like light, or heat, or Rontgen rays.” He thought he would be able to make such substance with the help of a new element which he had found.
Since that day we met almost every evening. Mr. Cavor lectured me on physics and I learnt a lot of interesting and unusual things.
His ideas interested me very much and I could not work at my play any longer. My head was busy with other things. I thought how to apply this substance to every branch of industry. Some days later I went to Mr. Cavor and told him that I wanted to be his fourth assistant.
substance – вещество
opaque – непроницаемый
rays – лучи

I. Complete the statements according to the text.
1. The author went to Mr. Cavor's laboratory because...
1) he wanted to know everything about Mr. Cavor's invention.
2) Mr. Cavor invited him.
3) he wanted to speak to Mr. Cavor about the play he was writing.
4) he wanted to write an article about Mr. Cavor.
2. Mr. Cavor's object of research work was...
1) a kind of radiant energy.
2) light, heat and Rontgen rays.
3) a new element.
4) a new substance.
3. Since the day of the author's visit to Mr. Cavor's laboratory...
1) the author got very interested in Mr. Cavor's invention and wanted to describe it in his play.
2) the author could not work at his play any longer.
3) Mr. Cavor asked him to become his fourth assistant.
4) they seldom met.

II. Choose the correct articles.
... possibilities of ... Substance opaque to heat and gravitation had no limits.
1) a, the 2) -, the 3) the, a 4) the, the

III. Change the sentence from Passive into Active:
All the intellectual work was done by Mr. Cavor.
1) Mr. Cavor had done all the intellectual work.
2) Mr. Cavor has done all the intellectual work.
3) Mr. Cavor did all the intellectual work.
4) Mr. Cavor was doing all the intellectual work.

IV. ‘To apply’ means:
1) to use 2) to sell 3) to offer 4) to examine