Exercise 13. Do the following puzzle. Use the information from the text

						1		2		3
														4
5				6								7
			8													9
10								11						12				13
					14
								15											16
			17
												18				19
										20
21		22								23
		24

Across:

2. Thick strong metal rope; a set of wires.

5. Injection-laser diode.

6. The act or process of sending out an electronic signal or message.

10. A material such as a rope that is made from a mass of natural or artificial threads.

11. Light-emitting diode.

12. A factory or place where power is produced.

17. A covering of a hard material, used as protection.

18. Article.

19. To last all through a period of time or to cover the whole of it.

21. The act of putting information.

23. The way in which light meets surface.

24. A system of talking to somebody else over long distance.

Down:

1. A series of connected things.

3. A structure such as a house.

4. Element.

5. Data.

7. A substance, especially a liquid, that can dissolve another substance.

8. An object or a piece of equipment that has been designed to do a particular job.

9. University area.

13. Television.

14. Condition of something or somebody.

15. Metal in the form of thin thread.

16. To dig through.

20. A long thin mark on the surface.

22. To move something on a particular place.