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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Architecture has social purposes and meets practical needs by means of combining art and technological innovations. In building construction, however, an emergence of new materials does not make its precursors obsolete, and architectural knowledge is cumulative. The fact that today much is constructed from prefabricated concrete does not do away with brick. Furthermore, despite dramatic changes and increased technological sophistication of architectural design and construction, the essential apparatus of erecting a building has remained rooted in preindustrial traditional practices passed down during the millennia. The social and utilitarian expectations of structures are largely based on elemental demands of keeping out elements and enemies, ameliorating the extremes of heat, and avoiding the instruction of wind, precipitation, and pests. Gravity, air pressure, and earthquakes can induce tensions that have to be accounted for when constructing functional enclosed space. Vertical stacking of masonry materials causes compression that can lead to important problems when a structure is spanned to build a roof and connect walls. Arches, vaults, and domes were specifically developed to alleviate the compression by directing the spanning element along a curve rather than a straight line. Building suspension structures, dams, and tunnels became possible in the nineteenth century with the increased availability of steel that could reinforce structural frames and enable them to withstand natural forces previously believed to be insurmountable.Functional evolutions of modern buildings create new demands on the analysis of structural behavior and engineering. Few occupants of skyscrapers view elevators as elaborate systems of vertical transportation. Humidity and temperature control, forced ventilation, natural and artificial lighting, sanitation and disposal of waste, electrical wiring, and fire prevention make very tall constructions engineering marvels that also must be aesthetically pleasing and physically convenient.Erecting a structure involves a great deal more than merely attending to the aesthetics and psychological experience of architectural space. The shape, size, and incombustibility of locally available construction materials fostered developments of specific technologies, and brick and stone masonry have evolved in response to the need for structural durability. Advances in civil engineering and knowledge associated with properties of building materials combine to lead to innovations in architectural design. Tools and skills required to exploit easily obtainable materials have continued to inform the development of modern industrialized technologies.
The purpose of paragraph 3 is to suggest that ________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions
The oceans are so vast and deep that until fairly recently, it was widely assumed that no matter how much trash and chemicals humans dumped into them, the effects would be negligible. Proponents of dumping in the oceans even had a catchphrase: "The solution to pollution is dilution."Today, we need look no further than the New Jersey-size dead zone that forms each summer in the Mississippi River Delta, or the thousand-mile-wide swath of decomposing plastic in the northern Pacific Ocean to see that this "dilution" policy has helped place a once flourishing ocean ecosystem on the brink of collapse.There is evidence that the oceans have suffered at the hands of mankind for millennia. But recent studies show that degradation, particularly of shoreline areas, has accelerated dramatically in the past three centuries as industrial discharge and run-off from farms and coastal cities have increased. Pollution is the introduction of harmful contaminants that are outside the norm for a given ecosystem. Common man-made pollutants reaching the oceans include pesticides, herbicides, chemical fertilizers, detergents, oil, sewage, plastics, and other solids. Many of these pollutants collect at the ocean's depths, where they are consumed by small marine organisms and introduced into the global food chain.Many ocean pollutants are released into the environment far upstream from coastlines. Nitrogen-rich fertilizers applied by farmers inland, for example, end up in local streams, rivers, and groundwater and are eventually deposited in estuaries, bays, and deltas. These excess nutrients can spawn massive blooms of algae that rob the water of oxygen, leaving areas where little or no marine life can exist.Solid wastes like bags, foam, and other items dumped into the oceans from land or by ships at sea are frequently consumed, with often fatal effects, by marine mammals, fish, and birds that mistake them for food. Discarded fishing nets drift for many years, ensnaring fish and mammals. In certain regions, ocean currents corral trillions of decomposing plastic items and other trash into gigantic, swirling garbage patches. One in the North Pacific, known as the Pacific Trash Vortex, is estimated to be the size of Texas.Pollution is not always physical. In large bodies of water, sound waves can carry undiminished for miles. The increased presence of loud or persistent sounds from ships, sonar devices, oil rigs, and even from natural sources like earthquakes can disrupt the migration, communication, and reproduction patterns of many marine animals, particularly aquatic mammals like whales and dolphins.
What does the passage mainly discuss?