Exercise 17. Discuss the following issues

Fun Facts about Lasers

Read the text and fill in gaps (1‑10) with the correct variant (A, B, C or D).

What kids haven’t played with lasers? We have all loved the laser fights in movies like Star Wars. Who wouldn’t want wield a laser around while fighting an enemy. Did you know that the term laser came from an acronym meaning “light amplification by stimulated emission of radiation.”? It should actually be all capitalized but for _______ (1) it isn’t.

The first working laser was actually _______ (2) by Theodore Maiman at the Hughes Research Laboratories back in 1960.

The strength of early lasers was measured in Gillette’s. This was the number of blue razor blades a beam could puncture.

There are many types of lasers found in everything from electronics to medical items. In the 60’s they were only seen as a solution for a _______ (3)!

Some lasers are gas, chemical, solid state, dye and stimulated electron lasers.

Lasers we come across today _______ (4) at a low level of power. Lasers in CD-ROMs drives will be around 5mW, DVD players around 5‑10mW, recordable CD drives ‑ 100mW.

The most ________ (5) laser recorded was at 1.25 petawatts in a laboratory in California in 1996.

Lasers actually are grouped into classes for levels of _______ (6). Class 1‑5. If you reach 5 it can mean permanent blindness and burning skin!

You may have thought that lasers are _______ (7) but they aren’t. So for a thief to try to get around them would be impossible!

Lasers could not be seen in space either because they have no matter. The matter causes the scattering effect which would give the appearance of a light beam.

Scientists are working on a laser to draw lightning strikes away from airports and power plants.

Cold lasers are used for acupuncture instead of needles.

There is a new laser that can detect cancer and diabetes called the “breathalyzer.”

Lasers are used to destroy and kill tumours.

Lasers are used to remove _______ (8).

They are used in eye surgeries and _______ (9) removals.

There is a laser technology called Clear Scan that can rid you of spider veins, vascular lesions and skin discolorations.

The world’s most powerful laser can have the power of a hydrogen
_______ (10)! That is amazing!

1.	a. hardness	b. simplicity	c. easy	d. fun
2.	a. demonstrated	b. fixed	c. demonstrating	d. seen
3.	a. issue	b. problem	c. question	d. task
4.	a. conduct	b. monitor	c. do	d. operate
5.	a. powerful	b. strong	c. heavy	d. easy
6.	a. danger	b. color	c. sound	d. difficulty
7.	a. watched	b. looked	c. visible	d. clear
8.	a. fingers	b. ears	c. hair	d. smell
9.	a. lipstick	b. mascara	c. nail polish	d. tattoo
10.	a. atom	b. bomb	c. isotope	d. atmosphere

1. How many facts about lasers are mentioned in the text and how often do we use lasers in our everyday life?

2. Do you know some facts that are not included to the list?

3. Which branch of science got the most benefit of lasers?

4. Can you invent any other usage of laser?

Дата добавления: 2015-01-03