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Many applications of silicate glasses derive from their optical transparency, which gives rise to one of silicate glasses' primary uses as window panes. Glass will transmit, reflect and refract light; these qualities can be enhanced by cutting and polishing to make optical lenses, prisms, fine glassware, and optical fibers for high speed data transmission by light. Glass can be colored by adding metallic salts, and can also be painted and printed with vitreous enamels. These qualities have led to the extensive use of glass in the manufacture of art objects and in particular, stained glass windows. Although brittle, silicate glass is extremely durable, and many examples of glass fragments exist from early glass-making cultures. Because glass can be formed or molded into any shape, and also because it is a sterile product, it has been traditionally used for vessels: bowls, vases, bottles, jars and drinking glasses. In its most solid forms it has also been used for paperweights, marbles, and beads. When extruded as glass fiber and matted as glass wool in a way to trap air, it becomes a thermal insulating material, and when these glass fibers are embedded into an organic polymer plastic, they are a key structural reinforcement part of the composite material fiberglass. Some objects historically were so commonly made of silicate glass that they are simply called by the name of the material, such as drinking glasses and reading glasses.
In what product are glass fibers used to hold dead air?
A: thermal insulating material

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Since their domestication, a large number of breeds of chickens have been established, but with the exception of the white Leghorn, most commercial birds are of hybrid origin. In about 1800, chickens began to be kept on a larger scale, and modern high-output poultry farms were present in the United Kingdom from around 1920 and became established in the United States soon after the Second World War. By the mid-20th century, the poultry meat-producing industry was of greater importance than the egg-laying industry. Poultry breeding has produced breeds and strains to fulfil different needs; light-framed, egg-laying birds that can produce 300 eggs a year; fast-growing, fleshy birds destined for consumption at a young age, and utility birds which produce both an acceptable number of eggs and a well-fleshed carcase. Male birds are unwanted in the egg-laying industry and can often be identified as soon as they are hatch for subsequent culling. In meat breeds, these birds are sometimes castrated (often chemically) to prevent aggression. The resulting bird, called a capon, has more tender and flavorful meat, as well.
When did the poultry business boom in the United States ?
A: By the mid-20th century, the poultry meat-producing industry was of greater importance than the egg-laying industry

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Maintaining continuity with his predecessors, John XXIII continued the gradual reform of the Roman liturgy, and published changes that resulted in the 1962 Roman Missal, the last typical edition containing the Tridentine Mass established in 1570 by Pope Pius V at the request of the Council of Trent and whose continued use Pope Benedict XVI authorized in 2007, under the conditions indicated in his motu proprio Summorum Pontificum. In response to the directives of the Second Vatican Council, later editions of the Roman Missal present the 1970 form of the Roman Rite.
What did Pope Benedict XVI continue the gradual reform of?
A: unanswerable

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In the past, a certain misconception sometimes led to the mistranslation of "szlachta" as "gentry" rather than "nobility".:206 :xvi This mistaken practice began due to the economic status of some szlachta members being inferior to that of the nobility in other European countries (see also Estates of the Realm regarding wealth and nobility). The szlachta included those almost rich and powerful enough to be magnates down to rascals with a noble lineage, no land, no castle, no money, no village, and no peasants.:xvi
Why did the mistranslation of szlachta come about?
A:
included those almost rich and powerful enough to be magnates down to rascals