Reading

Task 4. Read and translate the text. Find in the box the opposites to the italicized words from the text.

modern, carelessly, solid, hard, take, freeze, big, under, low, outside, changeably, equal, latest, cold

History of glassmaking

Glass is considered to be a physical state of matter. It may look solid, but it is a liquid as well. This is because glass has the hardness of crystal materials while also having a disordered arrangement of molecules like a liquid.

People first found and used glass made by nature. For example, lightning can create tubes of glass when it strikes sand that has the right combination of minerals.

Obsidian is a kind of black glass formed when the heat of a volcano melts the silica material in sand. Ancient cultures broke off pieces of obsidian to make knives and weapons such as arrows.

The chemical quality of glass is what makes up its colour. Impurities in glass such as iron can give it a green or brown colour. Adding chemicals to glass can give it different colour intensities and effects. For example, adding copper to glass can make it blue, while adding tin can make it white.

One of the earliest methods developed for making glass containers is called core forming. A glassmaker places a rounded piece of clay material on the end of a long metal stick. Once the clay dries, the glassmaker dips the form in a container of hot liquid glass until it is covered. The artist can then add a second colour of glass to make designs over the first layer of glass. Once the glass form cools completely, it is taken off the metal stick. The clay inside is carefully cut out to form a glass container.

Casting involves making a clay form in which the shape of the glass container is carved. Then, the artist puts small pieces of glass material inside of the clay form. When it is cooked at a very high temperature, the glass pieces melt and take the shape of the clay form. Once the solid glass object cools, an artist uses special tools to carve an opening in the container.

Glassblowing was first developed in the Roman Empire about two thousand years ago. It involves gathering hot liquid glass on the end of a metal pipe called a blowpipe. The glass reaches a temperature of about one thousand degrees Celsius. At this temperature the glass is a bright orange colour. A glassblower must turn the pipe constantly so that the thick liquid glass does not fall off the end. Then the pipe is blown through so that the glass expands into a rounded bubble form. The blown piece of glass can be worked and formed to create many different kinds of shapes. To reshape the glass, it must be continually reheated to stay soft.

Task 5. Answer the following questions to the text.

1. What may characterize glass as a physical state of matter?

2. In what way can glass be made by nature?

3. What is the chemical quality of glass?

4. What does the colour of glass depend on?

5. How is one of the earliest methods for making glass containers called?

6. In what way is a piece of clay material covered with the first layer of glass?

7. What is glass casting?

8. When was glassblowing first developed?

9. What temperature may be reached in glassblowing?

10. What must be done to reshape the glass?

Task 6. Decide which of the following statements are true (T) or false (F). If the statement is false, explain why.

1.	Glass may look solid, but it is also a liquid.
2.	Glass has a disordered arrangement of atoms like a liquid.
3.	Glass can be made by nature.
4.	When the heat of a volcano melts the silica material in sand a kind of black glass called obsidian is formed.
5.	Obsidian was used to make knives and arrows.
6.	Impurities and chemicals make up the chemical quality of glass.
7.	In core forming a glassmaker dips the form in a container of cold liquid glass until it is covered.
8.	Glassblowing involves making a clay form in which the shape of the glass container is carved.
9.	Casting involves gathering hot liquid glass on the end of a blowpipe.
10.	In glassblowing the pipe must be turned constantly so that the thick liquid glass falls off the end.

Task 7. Complete the phrases with the words from the text.

1. the chemical _______ of glass

2. _______combination of minerals

3. _______arrangement of molecules

4. different_______ intensities and effects

5. a rounded piece of _______ material

6. hot_______glass

7. to carve _______in the container

8. _______orange colour

9. to turn_______constantly

10. _______bubble form

Task 8. Match the columns to make the phrases and translate them.

1) glass	a) forming	1)
2) high	b) state	2)
3) silica	c) arrangement	3)
4) colour	d) material	4)
5) bubble	e) pipe	5)
6) physical	f) combination	6)
7) disordered	g) form	7)
8) core	h) intensity	8)
9) metal	i) temperature	9)
10) right	j) container	10)

Task 9. Match the words from the text with their definitions and compose your own sentence with the following words to illustrate their use.

1.	arrangement	a.	the physical world and everything in it that is not made by people
2.	glassblowing	b.	a small tubular instrument for directing a jet of air or other gas into a flame
3.	clay	c.	the flashing of light produced by a discharge of atmospheric electricity
4.	lightning	d.	a heavy, sticky material from the earth that is made into different shapes and becomes hard when it is dried
5.	nature	e.	a characteristic or feature that someone or something has
6.	state	f.	a transparent material consisting typically of a mixture of silicates
7.	sand	g.	the art of shaping a piece of hot, melted glass by blowing air into it through a tube
8.	quality	h.	the way that things or people are organized for a particular purpose or activity
9.	blowpipe	i.	a loose granular material that cover beaches, deserts, etc.
10.	glass	j.	the overall physical condition of something

1	2	3	4	5	6	7	8	9	10

Task 10. Match the columns to find the pairs of synonyms.

1) to carve	a) to spread over	1)
2) to develop	b) to shape	2)
3) to involve	c) to submerge	3)
4) to cover	d) to chill	4)
5) to add	e) to engrave	5)
6) to form	f) to include	6)
7) to dip	g) to engage	7)
8) to create	h) to elaborate	8)
9) to cool	i) to propel	9)
10) to blow	j) to produce	10)