7. Change the complex sentences given below according the examples and translate them:

Example A: While she was preparing for her physics exam she looked through all the notes of the lectures.

While preparing for her physics exam she looked through all the notes of the lectures.

1) While he was translating the article he used a dictionary.

2) While the engineer was working at the problem he made many experiments.

3) When the scientist was carrying out research in the field of nuclear physics he came to this institute to work here.

4) When the worker was applying the new method of work he got better results.

5) When the engineer was improving the design he made many calculations.

6) While he was experimenting with this substance he was very careful.

7) While the lecturer was describing this phenomenon he illustrated it with numerous examples.

8) When these scientists were working in our laboratory they obtained good results.

Example B: The scientists who are carrying out research into nuclear physics deal with the most difficult problems.

The scientists carrying out research into nuclear physics deal with the most difficult problems.

l) The scientist who is working at the method is well known.

2) The students who are listening to the typed lesson study at the evening faculty.

3) These postgraduate students who are watching the experiment work in our laboratory.

4) The worker who is repairing the machine is very skilled.

5) The engineer who is carrying out these investigations is well known inventor.

6) The students who are doing the laboratory work are from various faculties.

7)The workers who are building this installation will soon finish their work.

Lesson Two

I. Pre-text Exercises

1. Learn the meaning and pronunciation of the following words:

audio ['ɔ:diou], impurity [im'pjuəriti], accidentally [æksi'dentəli], boundary ['baundəri], crystal ['kristl], tough [tΛf], crucial ['kru:ʃjəl], allow [ə'lau], diode ['daiəd].

2. Read and remember the Plural of the following nouns:

basis ['beisis] - bases ['beisi:z]

axis ['æksis] - axes ['æksi:z]

analysis [ə'næləsis] - analyses [ə'næləsi:z]

criterion [krai'tiəriən] - criteria [krai'tiəriə]

II. Read the following text carefully, while you are reading look for the answers to the questions

1. What were the first diodes?

2. What makes the crystal work?

3. What is a crystal diode made of?

Text в Diodes

l. A diode is one of the important parts of the integrated circuit. A diode, or "rectifier", is any device through which electricity can flow in only one direction. The first diodes were crystals used as rectifiers in home radio kits. A weak radio signal was fed into the crystal through a very fine wire called a cat's whisker. The crystal removed the high frequency radio carrier signal, allowing the part of the signal with the audio information to come through loud and clear. The crystal was filled with impurities, making some sections more resistant to electrical flow than others. Using the radio required positioning the cat's whiskers over the right kind of impurity to get electricity to flow through the crystal to the output below it.

2. At the time, though, no one really understood about the impurities - then in 1939 Russell Ohl accidentally discovered that it was the boundary between sections of different purity that made the crystal work. Now that the way they work is understood, manufacturers make crystal diodes that work much more consistently than the ones in those original radio kits.

3. A crystal diode is made of two different types of semiconductors right next to each other. One side is easy for electrons to travel through; one side is much tougher. It's something like trying to swim through a pool filled with water and then a pool filled with mud: swimming through water is easy; swimming through mud is next to impossible. To an electron some semiconductors seem like water, some like mud.

4.One side of the semiconductor boundary is like mud, one like water. If you try to get electricity to move from the mud side to the water side, there's no problem. The electrons just jump across the boundary, forming a current. But try to make electricity go the other way and nothing will happen. Electrons that didn't have to work hard to travel around the water side just don't have enough energy to make it into the mud side. (In real life, there are always a few electrons that can trickle in the wrong direction, but not enough to make a big difference).

5. This boundary has turned out to be crucial for all daily lives. Diodes change the alternating current mat comes from your wall outlet into the direct current that most appliances need. And transistors need two such boundaries to work.