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In an age when waste today means a lack tomorrow, making use of every available resource becomes more and more important. As coal is being used in greater and greater amounts to produce electricity, larger amounts of ash, by-product of coal, are produced. When coal is burned in a boiler, two kinds of ash by-product are produced, a heavy bottom ash and a fine-as-powder fly ash that is filtered and captured by precipitators. About 10 to 15 percent of the coal by-product is bottom ash which is used like sand on icy city streets and highways and also on highways as paving material. It is the fly ash, however, that is receiving the greater amount of attention. Fly ash may be used as an additive to concrete in the construction of dams, bricks, and roads, and can replace up to 20 percent of the cement used in concrete. As a by-product of burned coal, fly ash requires no additional expenditure of energy to be produced, while cement production requires great amounts of energy.In addition to using fly ash as a concrete additive, the technology is available to extract the main mineral components-aluminum, silicon, and magnetic. Today, extracting these components is a very expensive process, but the time may come when it is cheaper to extract these products from ash than to mine new supplies. The first big, important step for an aspiring reporter is（）
25（）
Most people do not think of fishes and other sea animals as having voices, and of those who are aware of the fact that many of them can "speak", few understand that these "conversations" have significance. Actually, their talk may be as meaningful as much of our own. For example, some sea animals use their "voices" to locate their food in the ocean expanses (广阔的区域); others use their "voices" to let their fellows know of their locations; and still others, as a means of obtaining mates. Sometimes, "speaking" may even mean the difference between life and death to a sea animal. It appears in some cases that when a predator (食肉动物) approaches, the prey (被捕的动物) depends on no more than the sounds it makes to escape.Fish sounds are important to man, also. By listening to them, he can learn a great deal about the habits of creatures that make them, the size of the School they form, the patterns of their migrations, and the nature of the environments in which they live. He can also apply this information to the more effective utilization of the listening spots he has set up to detect enemy submarines (潜水艇). A knowledge of fish sounds can avoid confusion and unneeded effort when a "new" sound is picked up and the sound sentry (哨兵) must decide whether or not to call an alarm. The last sentence means that a knowledge of fish sounds can help man to （）
Questions 28-34Look at the following descriptions in scientific contribution in 2007 ( Questions 28-34 ) and the list of countries below.Match each description with the correct countries, A-J.Write the correct letter, A-J, in boxes 28-34 on your answer sheet.List of countriesA US B China C Europe D Japan E IndiaF Brazil G Singapore H South Korea I Russia J International The third has emerged in the country in terms of its share of patent offices.（）
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