Laser. Exercise 2.
Ответьте на вопросы, используя слова и словосочетания в скобках.
1. What is a laser? (a device producing an intensive beam of light) 2. What is its principle of operation? (light amplification by stimulated emission of radiation) 3. What light is produced by a laser? (light of pure single colour) 4. What can be done by means of a laser? (vaporizing the hardest materials) 5. What materials can be treated with a laser? (practically any material and any substance) 6. What is the most promising use of lasers? (the use in all kinds of communication) 7. What prevents putting into effect the projects to use lasers more widely in space? (great technological difficulties and great cost involved)