1. Find equivalents:

2. Complete the sentences:

1. Light is the form of energy that

2. It usually comes from

3. Light travels at a speed of

4. It travels in

5. Quanta are

6. Travelling of light in quanta enables it

7. Quantum theory explains

8. The word laser means (stands for)

9. Laser can pass

10. Light rays are reflected when

11. Refraction is a property of

12. Refraction occurs because

13. Red, green, blue colors are

14. The way different colors of light combine is known as

3. Answer the questions:

1. What form of energy is light?

2. What light rays are visible to human eye?

3. What is laser as a device used for?

4. How do atoms of the material behave when laser passes through them?

5. What rays does reflection involve?

6. What happens to light waves when they pass from one transparent material to another?

7. When can the speed of light be reduced?

8. When don’t light rays bend?

9. What occurs when you mix one primary color equally with another?

10. How can be got white light?

4. Translate the text «Fiber-optic communication» (Additional Reading) and discuss it with your partner.

5. Translate and do the summery of the text «Transparency and translucency» (Additional Reading).