阅读理解The passage most likely continues with a discussion of

阅读理解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 (5) electronic instruments―may include sounds that in the past would not have been 　　　 consdered musical Environmental 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 nonelectronic 　　　 instruments. Singers may be asked to scream, laugh, groan, sneeze, or to sing phonetic (10) 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. (15) Traditional percussion instruments are struck with new types of beaters; and instruments 　　　 that used to be couriered unconvennonal in Western music―tom-toms, bongos, 　　　 slapsticks, maracas―are widelv used. 　　　 In the search for novel sounds, increased use has been made in Western music of 　　　 Microtones. Non-Western music typically divides and interval between two pitches more (20) finely than Western music does, thereby producing a greter number of distinct tones, 　　　 or micro tones, within the same interval. Composers such as Krzysztof Pmderecki 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 (25) 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 graphlike diagrams, new note shapes and symbols, and 　　　 novel ways of arranging notation on the page.

阅读理解Meteorite Impact and Dinosaur Extinction There is increasing evidence that the impacts of meteorites have had important effects on Earth, particularly in the field of biological evolution

阅读理解According to the passage, the National Sculpture Society promoted the production of sculpture by doing which of the following?

阅读理解Swimming Machines Tunas, mackerels, and billfishes (marlins, sailfishes, and swordfish) swim continuously

阅读理解According to the passage, the flat-topped mounds in Mississippian towns were used for all of the following purposes EXCEPT

阅读理解Under the Earth''s topsoil, at various levels, sometimes under a layer of rock, there am 　　　 deposits of clay. Look at cuts where highways have been built to see exposed clay beds; or 　　　 look at a construction site, where pockets of clay may be exposed. Rivers also reveal clay along their banks, and erosion on a hillside may make clay easily accessible. (5)　 What is clay made oF The Earth''s surface is basically rock, and it is this rock that 　　　 gradually decomposes into clay. Rain, streams, alternating freezing and thawing, roots of 　　　 trees and plants forcing their way into cracks, earthquakes, volcanic action, and glaciers-all 　　　 of these forces slowly break down the Earth''s exposed rocky crust into smaller and smaller 　　　 pieces that eventually become clay. (10)　 Rocks are composed of elements and compounds of elements. Feldspar, which is the 　　　 most abundant mineral on the Earth''s surface, is basically made up of the oxides silica and 　　　 alumina combined with alkalies like potassium and some so-called impurities such as iron. 　　　 Feldspar is an essential component of granite rocks, and as such it is the basis of clay. 　　　 When it is wet, clay can be easily shaped to make a variety of useful objects, which can (15)　 then be fired to varying degrees of hardness and covered with impermeable decorative 　　　 coatings of glasslike material called glaze. Just as volcanic action, with its intense heat, 　　　 fuses the elements in certain rocks into a glasslike rock called obsidian, so can we apply 　　　 heat to earthen materials and change them into a hard, dense material. Different clays need 　　　 different heat levels to fuse, and some, the low-fire clays, never become nonporous and (20)　 watertight like highly fired stoneware. Each clay can stand only a certain amount of heat 　　　 without losing its shape throughsagging or melting. Variations of clay composition and the 　　　 temperatures at which they are fired account for the differences in texture and appearance 　　　 between a china teacup and an earthenware flowerpot.

阅读理解Of all modern instruments, the violin is apparently one of the simplest. It consists in essence of a hollow, varnished wooden sound box, or resonator, and a long neck, covered with a fingerboard, along which four strings are stretched at high tension. The beauty of design, shape, and decoration is no accident: the proportions of the instrument are (5) determined almost entirely by acoustical considerations. Its simplicity of appearance is deceptive. About 70 parts are involved in the construction of a violin, Its tone and its outstanding range of expressiveness make it an ideal solo instrument. No less important. however, is its role as an orchestral and chamber instrument. In combination with the larger and deeper-sounding members of the same family, the violins form the nucleus (10)of the modern symphony orchestra. The violin has been in existence since about 1550. Its importance as an instrument in its own right dates from the early 1600''s, when it first became standard in Italian opera orchestras. Its stature as an orchestral instrument was raised further when in 1626 Louis XIII of France established at his court the orchestra known as Les vingt-quatre (15)violons du Roy (The King''s 24 Violins), which was to become widely famous later in the century. In its early history, the violin had a dull and rather quiet tone resulting from the fact that the strings were thick and were attached to the body of the instrument very loosely. During the eighteenth and nineteenth century, exciting technical changes were inspired (20)by such composer-violinists as Vivaldi and Tartini. Their instrumental compositions demanded a fuller, clearer, and more brilliant tone that was produced by using thinner strings and a far higher string tension. Small changes had to be made to the violin''s internal structure and to the fingerboard so that they could withstand the extra strain. Accordingly, a higher standard of performance was achieved, in terms of both facility (25)and interpretation. Left-hand technique was considerably elaborated, and new fingering patterns on the fingerboard were developed for very high notes.

阅读理解The Origins of Theater In seeking to describe the origins of theater, one must rely primarily on speculation, since there is little concrete evidence on which to draw

阅读理解The Origin of the Pecific Island People The greater Pacific region, traditionally called Oceania, consists of three cultural areas: Melanesia, Micronesia, and Polynesia

阅读理解Groundwater Groundwater is the word used to describe water that saturates the ground, filling all the available spaces

阅读理解The wide variety of climates in North America has helped spawn a complex pattern of 　　 soil regions. In general, the realm''s soils also reflect the broad environmental partitioning 　　 into "humid America" and "arid America." Where annual precipitation exceeds 20 inches 　　 (50 centimeters),soils in humid areas tend to be acidic in chemical content, Since crops (5) do best in soils that ale neither acidic(higher in acid content) nor alkaline(higher in salt 　 　content).fertilization is necessary to achieve the desired level of neutrality between the 　 　two. Arid America''s soils are typically alkaline and must be fertilized back toward 　 　neutrality by adding acidic compounds. Although many of these dryland soils, particularly 　 　in the Great Plains, are quite fertile, European settlers learned over a century ago that (10) water is the main missing ingredient in achieving their agricultural potential. In the 　 　1970''s, certain irrigation methods were perfected and finally provided a real opportunity 　 　to expand more intensive farming west from the Central Lowland into the drier portions 　 　of the Great Plains. Glaciation also enhanced the rich legacy of fertile soils in the central 　 　United States, both from the deposition of mineral-rich glacial debris left by meltwater (15) and from thick layers of fine wind-blown glacial material, called loess, in and around the 　 　middle Mississippi Valley. 　 　 Natural vegetation patterns could be displayed on a map of North America, but the 　 　enormous human modification of the North American environment in modem times has 　 　all but reduced this regionalization scheme to the level of the hypothetical. Nonetheless, (20) the humid America-arid America dichotomy is still a valid generalization: the natural 　 　vegetation of areas receiving more than 20 inches of water yearly is forest, whereas the 　 　drier climates give rise to a grassland cover. The forests of North America tent to make 　 　a broad transition by latitude. In the Canadian North, needle-leaf forests dominate, but 　 　these coniferous trees become mixed with broadleaf deciduous trees as one crosses the (25) border into the Northeast United States As one proceeds toward the Southeast, broadleaf vegetation 　 　becomes dominant. Arid America mostly consists of short-grass prairies or 　 　stepper. The only areas of true desert are in the Southwest.

阅读理解Powering the Industrial Revolution In Britain one of the most dramatic changes of the Industrial Revolution was the harnessing of power．Until the reign of George Ⅲ(1760-1820)，available sources of power for work and travel had not increased since the Middle Ages

阅读理解Reflection in Teaching Teachers, it is thought, benefit from the practice of reflection, the conscious act of thinking deeply about and carefully examining the interactions and events within their own classrooms

阅读理解Why does the author mention grasshoppers in line 28?

阅读理解Which of the following can be inferred from the passage about rocks that are found in areas where ice is common?

阅读理解Because the low latitudes of the Earth, the areas near the equator, receive more heat 　　　 Than the latitudes near the poles, and because the nature of heat is to expand and move, 　　　 Heat is transported from the tropics to the middle and high latitudes. Some of this heat is Moved by winds and some by ocean currents, and some gets stored in the atmosphere in (5)　 the form of latent heat. The term "latent heat" refers to the energy that has to be used to 　　　 Convert liquid water to water vapor. We know that if we warm a pan of water on a stove, 　　　 it will evaporate, or turn into vapor, faster than if it is allowed to sit at room temperature. 　　　 We also know that if we hang wet clothes outside in the summertime they will dry faster 　　　 than in winter, when temperatures are colder. The energy used in both cases to change (10)　 liquid water to water vapor is supplied by heat―supplied by the stove in the first case 　　　 and by the Sun in the latter case. This energy is not lost. It is stored in water vapor in the 　　　 atmosphere as latent heat. Eventually, the water stored as vapor in the atmosphere will 　　　 condense to liquid again, and the energy will be released to the atmosphere. 　　　　　 In the atmosphere, a large portion of the Sun''s incoming energy is used to evaporate (15)　 Water, primarily in the tropical oceans. Scientists have tried to quantify this proportion 　　　 of the Sun''s energy. By analyzing temperature, water vapor, and wind data around the 　　　 globe, they have estimated the quantity to be about 90 watts per square meter, or nearly 　　　 30 percent of the Sun''s energy. Once this latent heat is stored within the atmosphere, it 　　　 can be transported, primarily to higher latitudes, by prevailing, large-scale winds. Or it (20)　 can be transported vertically to higher levels in the atmosphere, where it forms clouds 　　　 and subsequent storms, which then release the energy back to the atmosphere.

阅读理解The passage mentions “a baby’s face” inline 26 as an example of a

阅读理解Architecture Architecture is the art and science of designing structures that organize and enclose space for practical and symbolic purposes

阅读理解What unusual or unique biological train led to the remarkable diversification and 　　　 unchallenged success of the ants for ever 50 million years? The answer appears to be 　　　 that they were the first group of predatory ensocial insects that both lived and foraged 　　　 primarily in the soil and in rotting vegetation on the ground. Eusocial refers to a form (5) of insect society characterized by specialization of tasks and cooperative care of the 　　　 young; it is rare among insects. Richly organized colonies of the land made possible 　　　 by eusociality enjoy several key advantages over solitary individuals. 　　　 Under most circumstances groups of workers arc better able to forage for food and 　　　 defend the nest, because they can switch from individual to group response and back (10) again swiftly and according to need. When a food object or nest intruder is too large for 　　　 one individual to handle, nestmates can be quickly assembled by alarm or recruitment 　　　 signals. Equally important is the fact that the execution of multiple-step tasks is 　　　 accomplished in a series-parallel sequence. That is, individual ants can specialize in 　　　 particular steps, moving from one object (such as a larva to be fed) to another (a second (15) larva to be fed). They do not need to carry each task to completion from start to finish. 　　　 for example, to check the larva first, then collect the food, then feed the larva. Hence, if 　　　 each link in the chain has many workers in attendance, a senes directed at any particular 　　　 object is less likely to fail. Moreover, ants specializing in particular labor categories 　　　 typically constitute a caste specialized by age or body form or both. There has bees some (20) documentation of the superiority in performance and net energetic yield of various castes 　　　 for their modal tasks, although careful experimental studies are still relatively few. 　　　 What makes ants unusual in the company of eusocial insects is the fact that they are 　　　 the only eusocial predators (predators are animals that capture and feed on other animals) 　　　 occupying the soil and ground litter. The eusocial termites live in the same places as ants 　　　 and also have wingless workers, but they feed almost exclusively on dead vegetation.