An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful subtances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

    Many of the more important air pollutants, such as sulfur oxides, carbon monoxide, and notrigen oxides, are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature’s output of these compounds dwarfs that resulting from human activities.

          However, human production usually occurs in a localized area, such as as city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a subtance to be a pollutant; in fact, the numerial value tells us little until we know how much of an increase this represents over ther concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, has a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

According to the passage, the numerical value of the concentration level of a substance is only useful if ________.

Composers today use a wider variety of sounds than ever before, including many that were once considered undesirable noises. Composer Edgard Varese (1883-1965)  called thus the “liberation of sound…the right to make music with any and all sounds.” Electronic music, for example – made with the aid of computers, synthesizers, and electronic instruments – may include sounds that in the past would not have been considered musical.

          Enviromental sounds, such as thunder, and electronically generated hisses and blips can be recorded, manipulated, and then incorporated into a musical composition. But composers also draw novel sounds from voices and non-electronic instruments. Singers may be asked to scream, laugh, groan, sneeze, or to sing phonetic sounds rather than words. Wind and string players may lap or scrape their instruments. A brass or woodwind player may hum while playing, to produce two pitches at once; a pianist may reach inside the piano to pluck a string and then run a metal blade along it. In the music of the Western world, the greatest expansion and experimentation have involved percussion instruments, which outnumber strings and winds in many recent compositions. Traditional persussion instruments are struck with new types of beaters; and instruments that used to be couriered unconventional in Western music – tom-toms, bongos, slapsticks, maracas – are widely used.

          In the search for novel sounds, increased use has been made in Western music of Microtones. Non-Western music typically divides and intervals between two pitches more finely than Western music does, thereby producing a greater number of distinct tones or micro tones, within the same interval. Composers such as Krzysztof Penderecki create sound that borders on electronic noise through tone clusters – closely spaced tones played together and heard as a mass, block, or band of sound. The directional aspect of sound has taken on new importance as well Loudspeakers or groups of instruments may be placed at opposite ends of the stage, in the balcony, or at the back and sides of the auditorium. Because standard music notation makes no provision for many of these innovations, recent music scores may contain graph like diagrams, new note shapes and symbols, and novel ways of arranging notation on the page.

According to the passage, which of the following types of instruments has played a role in much of the innovation in Western music?

Mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the followingquestions.

He was so mean that he could not bear to ________ the smallest sum of money for the charity appeal.

Mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the following questions.

They appreciate ________ this information

Mark the letter A,B,C or D on our answer sheet to indicate the underlined part that needs correction in each of the following questions.

Lasers are of great value in areas such as communication, industry, medicines and scientific research.

Mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the following questions.

Yuki and Hana are having a free afternoon. Yuki is inviting Hana to see a new movie with him.

Yuki: “Do you feel like going to the cinema this afternoon?”

Hana: : ________.”

Composers today use a wider variety of sounds than ever before, including many that were once considered undesirable noises. Composer Edgard Varese (1883-1965)  called thus the “liberation of sound…the right to make music with any and all sounds.” Electronic music, for example – made with the aid of computers, synthesizers, and electronic instruments – may include sounds that in the past would not have been considered musical.

          Enviromental sounds, such as thunder, and electronically generated hisses and blips can be recorded, manipulated, and then incorporated into a musical composition. But composers also draw novel sounds from voices and non-electronic instruments. Singers may be asked to scream, laugh, groan, sneeze, or to sing phonetic sounds rather than words. Wind and string players may lap or scrape their instruments. A brass or woodwind player may hum while playing, to produce two pitches at once; a pianist may reach inside the piano to pluck a string and then run a metal blade along it. In the music of the Western world, the greatest expansion and experimentation have involved percussion instruments, which outnumber strings and winds in many recent compositions. Traditional persussion instruments are struck with new types of beaters; and instruments that used to be couriered unconventional in Western music – tom-toms, bongos, slapsticks, maracas – are widely used.

          In the search for novel sounds, increased use has been made in Western music of Microtones. Non-Western music typically divides and intervals between two pitches more finely than Western music does, thereby producing a greater number of distinct tones or micro tones, within the same interval. Composers such as Krzysztof Penderecki create sound that borders on electronic noise through tone clusters – closely spaced tones played together and heard as a mass, block, or band of sound. The directional aspect of sound has taken on new importance as well Loudspeakers or groups of instruments may be placed at opposite ends of the stage, in the balcony, or at the back and sides of the auditorium. Because standard music notation makes no provision for many of these innovations, recent music scores may contain graph like diagrams, new note shapes and symbols, and novel ways of arranging notation on the page.

According to the passage, Krzysztof Pederecki is known for which of the following practices?

Composers today use a wider variety of sounds than ever before, including many that were once considered undesirable noises. Composer Edgard Varese (1883-1965)  called thus the “liberation of sound…the right to make music with any and all sounds.” Electronic music, for example – made with the aid of computers, synthesizers, and electronic instruments – may include sounds that in the past would not have been considered musical.

          Enviromental sounds, such as thunder, and electronically generated hisses and blips can be recorded, manipulated, and then incorporated into a musical composition. But composers also draw novel sounds from voices and non-electronic instruments. Singers may be asked to scream, laugh, groan, sneeze, or to sing phonetic sounds rather than words. Wind and string players may lap or scrape their instruments. A brass or woodwind player may hum while playing, to produce two pitches at once; a pianist may reach inside the piano to pluck a string and then run a metal blade along it. In the music of the Western world, the greatest expansion and experimentation have involved percussion instruments, which outnumber strings and winds in many recent compositions. Traditional persussion instruments are struck with new types of beaters; and instruments that used to be couriered unconventional in Western music – tom-toms, bongos, slapsticks, maracas – are widely used.

          In the search for novel sounds, increased use has been made in Western music of Microtones. Non-Western music typically divides and intervals between two pitches more finely than Western music does, thereby producing a greater number of distinct tones or micro tones, within the same interval. Composers such as Krzysztof Penderecki create sound that borders on electronic noise through tone clusters – closely spaced tones played together and heard as a mass, block, or band of sound. The directional aspect of sound has taken on new importance as well Loudspeakers or groups of instruments may be placed at opposite ends of the stage, in the balcony, or at the back and sides of the auditorium. Because standard music notation makes no provision for many of these innovations, recent music scores may contain graph like diagrams, new note shapes and symbols, and novel ways of arranging notation on the page.

The passage suggests that Edgard Varese is an example of a composer who ________ .