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2007年诺贝尔化学奖得主﹣﹣德国科学家格哈德•埃特尔通过对有关一氧化碳在金属铂表面的氧化过程的研究,发明了汽车尾气净化装置.净化装置中的催化转化器,可将CO、NO、NO2和碳氢化合物等转化为无害的物质,有效降低尾气对环境的危害.下列有关说法不正确的是(  )

A:催化转化器中的铂催化剂可加快CO的氧化

B:铂表面做成蜂窝状更有利于提高催化效果

C:在铂催化下,NO  NO2可被CO还原成N2

D:碳氢化合物在铂催化下,被CO直接氧化成CO2和H2O

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D

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    Disposing(处理) of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities, the waste-disposal problem becomes increasingly difficult.

    During the eighteenth century, it was usual for several neighboring towns to get together to select a faraway spot as a dumpsite. Residents or trash haulers(垃圾托运者) would transport household rubbish, rotted wood, and old possessions to the site. Periodically(定期的) some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by.

    Factories, mills, and other industrial sites also had waste to be disposed of. Those located on rivers often just dumped the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

    Several facts make these choices unacceptable to modern society. The first problem is space. Dumps, which are now called landfills, are most needed in heavily populated areas. Such areas rarely have empty land suitable for this purpose. Property is either too expensive or too close to residential(住宅区的)neighborhoods. Long-distance trash hauling has been a common practice, but once farm areas are refusing to accept rubbish from elsewhere, cheap land within trucking distance of major city areas is almost nonexistent.

    Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers, ground water, land and air is a price people can no longer pay to get rid of waste. The amount of waste, however, continues to grow.

    Recycling efforts have become commonplace, and many towns require their people to take part. Even the most efficient recycling programs, however, can hope to deal with only about 50 percent of a city's reusable waste.