- •Unit 5. НазВание?
- •The laser technology today and tomorrow
- •5.1. Read the following words and expressions and try to guess their meaning.
- •5.2. Read the following words and notice their pronunciation.
- •5.3. Translate the following word-groups.
- •5.4. Read the text. The laser technology today and tomorrow
- •5.5. Choose the correct variant and complete the following sentences.
- •5.6. Read the following statements and decide if they are true (t) or false (f).
- •5.7. Choose the correct answer to the following questions.
- •5.8. Write the correct question for the following sentences, as in the model.
- •5.9. Work in pairs and discuss the answers to the following questions.
- •Memorize the following words and expressions
- •5.13. Read the text. Robots
- •5.14. Arrange these sentences in order to make a logical paragraph paying attention to the dates.
- •5.15. Answer the questions to the text.
- •5.16. Discuss the following.
- •Complex Sentences
- •5.17. Translate the following sentences paying attention to conditional clauses.
- •5.18. Link these statements using an appropriate time clause using conjunctions until, when, as, once, before, after.
- •5.19. Translate the following sentences paying attention to the clauses.
- •5.20. Translate the sentences.
5.5. Choose the correct variant and complete the following sentences.
1. When lasers were first invented in 1960, …
a) the thought of completely new applications has generated the excitement over the laser.
b) nobody knew the limits to which these devices would be used.
c) nobody knew quite well what to do with them.
2. The first lasers were called …
a) “a solution waiting for a problem”.
b) “a problem waiting for a solution”.
c) “a solution of all the problems”.
3. The laser forces its atoms to emit …
a) rays having different length and traveling in the same direction.
b) rays having the same length and traveling in the same direction.
c) rays having the same length traveling in different direction.
4. Since the invention of the laser scientists …
a) have developed several types of it.
b) have developed CO2 gas laser only.
c) have developed semiconductor laser only.
5. The semiconductor laser is …
a) a few hundreds of a millimeter long.
b) a few thousands of a millimeter long.
c) a few tens of a millimeter long.
6. The invention of the laser has helped the scientists …
a) to calculate the speed of light more precisely than ever before.
b) to calculate the distance between all the planets of solar system.
c) to calculate the speed of space shuttles from the Earth to the moon.
5.6. Read the following statements and decide if they are true (t) or false (f).
A laser concentrates light waves into a very intense beam.
With lasers, all the light waves have different wavelength.
Atoms are made of electrons and protons.
The energy is given off by the electrons as invisible light.
The laser is used in medicine.
The radiation density of semiconductor laser and ruby laser is the same.
The laser will be widely used in communication.
5.7. 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 a laser be 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 used as a means of measurement?
a) The strength.
b) The accuracy.
c) The sensitivity.
5. What 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.
5.8. 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. (In what sphere … )
– In what sphere of technology will the lasers be used in the nearest future?
1. Lasers produce pure, intense beams of light and radiation. (What…)
2. The invention of the laser was called “a solution waiting for a problem”. (How …)
3. Surgeons performing operations have found the laser as a surgical knife which is able to make bloodless incisions. (Who …)
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. (What …)
6. It is the field of communication where the laser technology will find the most extensive application in future. (Where …)
7. The use of laser reflectors allowed the American astronauts to determine the exact distance from the moon to the Earth. (What …)
8. The most interesting thing about the semiconductor laser is its ability to transform electrical energy directly into the light wave one. (What …)
9. Semiconductor quantum generators were developed in 1960. (When …)
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.