Read the following passage and choose the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 33 to 42.    

A useful definition of an air pollutant is a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetations, 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 substances 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 nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. 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 form human activities. However, human production usually occurs in a localized area, such as a city.     In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. 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 substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the 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.

Which of the following is best supported by the passage?

A. To effectively control pollution local government should regularly review their air pollution laws. 

B. One of the most important steps in preserving natural lands is to better enforce air pollution laws. 

C. Scientists should be consulted in order to establish uniform limits for all air pollutants. 

D. Human activities have been effective in reducing air pollution.

Read the following passage and mark the letter A, B, C or D on you answer sheet to indicate the correct answer to each of the questions

When jazz began to lose its reputation as “low-down” music and to gain well-deserved acclaim among intellectuals, musicians began to feature many instruments previously considered inappropriate for jazz. Whereas before the 1950s, jazz musicians played only eight basic instruments in strict tempo, in this decade they started to improvise on the flute, electric organ, piccolo, accordion, cello, and even bagpipes, with the rhythm section composed for strings or piano. Big bands no longer dominated jazz, and most changes emerged from small combos, such as the Dave Brubeck Quartet and the Gerry Mulligan Quartet. The Gerry Mulligan Quartet proved that a small, modern band could sound complete without a piano; the rhythm section consisted only of a set of drums and a string bass.

Jazz continued to move in new directions during the 1960s. Saxophonist and composer Ornette Coleman led a quartet playing “free” jazz that was atonal. Pianist Cecil Taylor also conducted similar experiments with music, and John Coltrane included melodies from India in his compositions. In the 1970s, musicians blended jazz and rock music into fusion jazz which combined the melodies and the improvisations of jazz with the rhythmic qualities of rock ‘n’ roll, with three or five beats to the bar and in other meter. The form of jazz music was greatly affected by electric instruments and electronic implements to intensify, distort, or amplify their sounds. However, the younger musicians of the time felt compelled to include a steady, swinging rhythm which they saw as a permanent and essential element in great jazz.

The author of the passage mentions all of the following EXCEPT _______

A. bagpipes

B. percussion

C. string bass

D. harpsichord