5.Surgeons have found the laser as a “surgical knife”, able to make bloodless incisions.

6.It’s impossible to foresee the day when a single laser beam will be employed to carry simultaneously millions of telephone conversations.

7.The laser will be used for fast communications under the sea and across continents.

8.The invention of lasers is one of the least important achievements in science and technology.

11.7. Choose the correct answer to the following questions.

1.What is a laser?

a)It is a device which converts one form of energy into another.

b)It is a device which produces pure intense beams of light and

radiation.

c)It is a device which transmits electrical energy into the nuclear one.

2.Which of the following directions can be a laser used in?

a)It can be used for cooking meals.

b)It can be used in the system of education.

c)It can be used in eye surgery.

3.What gas is used to cut through brick and granite?

a)CO2.

b)Argon.

c)Helium.

4.Which of the laser qualities is being exploited as a means of measurement?

a)The strength.

b)The accuracy.

c)The sensitivity.

5.How much is the density of semiconductor laser radiation?

a)It is hundreds of thousands of times smaller than that of the best ruby laser.

b)It is thousands of times smaller than that of the best ruby laser.

с) It is hundreds of thousands of times greater than that of the best ruby laser.

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11.8.Write the correct question for the following sentences, as in the model.

Model: – In the nearest future lasers will be used in the sphere of communication.

–What sphere of technology will the lasers be used in the nearest future?

1.Lasers produce pure, intense beams of light and radiation.

2.The invention of the laser was called “a solution waiting for a problem”.

3.Surgeons performing operations have found the laser as a surgical knife which is able to make bloodless incisions.

4.Yes, it is. The semiconductor laser is able to transform electrical energy directly into the light wave one.

5.The accuracy of the laser beam has allowed the scientists to calculate the speed of light more precisely.

6.It is the field of communication where the laser technology will find the most extensive application in future.

7.The use of laser reflectors allowed the American astronauts to determine the exact distance from the moon to the Earth.

8.The most interesting thing about the semiconductor laser is its ability to transform electrical energy directly into the light wave one.

9.Semiconductor quantum generators were developed in 1960.

10.Yes, there is. There are a lot of possibilities for the laser technology not only in science and technology, but in everyday life, either.

11.The laser will find its most extensive application in the sphere of communication.

12.The accuracy of the laser has allowed the scientists to calculate the speed of light.

11.9.Put the words in the right order to make sentences, as in the model.

Model: – a multipurpose tool. / Nowadays / the laser / has become

–Nowadays the laser has become a multipurpose tool.

1. several / types / Scientists / have developed / of / lasers.

2.can be focused / very precisely/ The laser beam / in a very small area.

3.are being opened. / laser application / New areas of

4.The laser / can be used / cancer treatment. / as a means of

5.was / invented / in 1962. / Semiconductor / generator

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Gerund

11.10.Combine the two sentences changing the second one into by + gerund.

Model: – The machine was tested. We increased the load.

–The machine was tested by increasing the load.

1.The changes were traced. We stained the preparation.

2.The condition was created. We increased the pressure.

3.A better result was obtained. We combined these methods.

4.The components were separated. We centrifuged the medium.

5.The defect was reduced. We replaced some parts of the apparatus.

6.The result was checked. We used another technique.

7.The reaction rate was increased. We increased the temperature.

8.We found the error. We repeated the experiment.

11.11.Combine the two sentences changing one of them into gerund construction.

Model: – We should exchange preprints of papers. The idea is good enough.

–The idea of exchanging preprints of papers is good enough.

1.We should re-examine this conception. The necessity for this is great.

2.We must collect statistical information but the procedure is time-consuming.

3.We should look for a compromise solution. The idea is reasonable.

4.We should use this approach. The advantage of this is beyond doubt.

5.We can test the samples. The procedure is simple.

6.We can measure the density. The method is accurate enough.

7.We should localize the defect but the problem presents much difficulty.

8.We should look for a better technique. The idea seems reasonable.

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