When we think of green buildings, we tend to think of new ones—the kind of high-tech, solar-paneled masterpieces that make the covers of architecture magazines. But the U.S. has more than 100 million existing homes, and it would be (1) wasteful to tear them all down and (2) them with greener versions. An enormous amount of energy and resources went into the construction of those houses. And it would take an average of 65 years for the (3) carbon emissions from a new energy-efficient home to make up for the resources lost by destroying an old one. So in the broadest (4) , the greenest home is the one that has already been built. But at the same time, nearly half of U.S. carbon emissions come from heating, cooling and (5) our homes, offices and other buildings. "You can’t deal with climate change without dealing with existing buildings," says Richard Moe, the president of the National Trust.With some (6) , the oldest homes tend to be the least energy-efficient. Houses built before 1939 use about 50% more energy per square foot than those built after 2000, mainly due to the tiny cracks and gaps that (7) over time and let in more outside air.Fortunately, there are a (8) number of relatively simple changes that can green older homes, from (9) ones like Lincoln’s Cottage to your own postwar home. And efficiency upgrades (升级) can save more than just the earth; they can help (10) property owners from rising power costs.A.accommodationsB.clumsyC.doubtfulD.exceptionsE.expandF.historicG.incrediblyH.poweringI.protectJ.reducedK.replaceL.senseM.shiftedN.supplyingO.vast (9)处应填()
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With the world’s population estimated to grow from six to nine billion by 2050, researchers, businesses and governments are already dealing with the impact this increase will have on everything from food and water to infrastructure (基础设施) and jobs. Underlying all this (1) will be the demand for energy, which is expected to double over the next 40 years.Finding the resources to meet this demand in a (2) sustainable way is the cornerstone (基石) of our nation’s energy security, and will be one of the major (3) of the 21st century. Alternative forms of energy—bio-fuels, wind and solar, to name a few—are 4 being funded and developed, and will play a growing (5) in the world’s energy supply. But experts say that, even when (6) , alternative energy sources will likely meet only about 30% of the world’s energy needs by 2050.For example, even with (7) investments, such as the $93 million for wind energy development (8) in the American Recovery and Reinvestment Act, important alternative energy sources such as wind and bio-fuels (9) only about 1% of the market today.Energy and sustainability experts say the answer to our future energy needs will likely come from a lot of (10) —both traditional and alternative.A.stableB.solutionsC.significantD.roleE.progressF.marvelousG.includedH.growthI.exactlyJ.consistK.compriseL.competitionsM.combinedN.challengesO.certainly (9)处应填()
So many people use the cell phones so frequently every day. But (1) little is certain about the health effects of its use. Manufacturers (2) that cell phones meet government standards for safe radio-frequency radiation emission, but enough studies are beginning to document a possible (3) in rare brain tumors (肿瘤), headaches and behavioral disorders in children to cause concern. So far, the evidence isn’t (4) on whether the use of cell phones (5) to any increased risk of cancer. In a new trial, researchers asked 47 volunteers to (6) in a project to measure glucose (葡萄糖) consumption in the brain by scanning the brain to see how cells use energy. For both 50-minute scans, the volunteers had a cell phone (7) to each ear. During the first scan, the devices were turned off, but for the second scan, the phone on the right ear was (8) on and received a recorded-message call, although the volume was muted (消音) so the noise wouldn’t bias the results. The results of the second scan showed that the (9) of the brain nearest to the device had higher rates of glucose consumption than the rest of the brain. The study shows that cell phones can change brain activity, and (10) a whole new avenue for scientific inquiry, though it doesn’t say anything about whether cell-phone radiation can cause cancer.A.conclusiveB.contributesC.deriveD.expressesE.fixedF.immenselyG.increaseH.maintainI.missionJ.participateK.particularL.providesM.regionsN.surprisinglyO.switched (10)处应填()
So many people use the cell phones so frequently every day. But (1) little is certain about the health effects of its use. Manufacturers (2) that cell phones meet government standards for safe radio-frequency radiation emission, but enough studies are beginning to document a possible (3) in rare brain tumors (肿瘤), headaches and behavioral disorders in children to cause concern. So far, the evidence isn’t (4) on whether the use of cell phones (5) to any increased risk of cancer. In a new trial, researchers asked 47 volunteers to (6) in a project to measure glucose (葡萄糖) consumption in the brain by scanning the brain to see how cells use energy. For both 50-minute scans, the volunteers had a cell phone (7) to each ear. During the first scan, the devices were turned off, but for the second scan, the phone on the right ear was (8) on and received a recorded-message call, although the volume was muted (消音) so the noise wouldn’t bias the results. The results of the second scan showed that the (9) of the brain nearest to the device had higher rates of glucose consumption than the rest of the brain. The study shows that cell phones can change brain activity, and (10) a whole new avenue for scientific inquiry, though it doesn’t say anything about whether cell-phone radiation can cause cancer.A.conclusiveB.contributesC.deriveD.expressesE.fixedF.immenselyG.increaseH.maintainI.missionJ.participateK.particularL.providesM.regionsN.surprisinglyO.switched (9)处应填()
With the world’s population estimated to grow from six to nine billion by 2050, researchers, businesses and governments are already dealing with the impact this increase will have on everything from food and water to infrastructure (基础设施) and jobs. Underlying all this (1) will be the demand for energy, which is expected to double over the next 40 years.Finding the resources to meet this demand in a (2) sustainable way is the cornerstone (基石) of our nation’s energy security, and will be one of the major (3) of the 21st century. Alternative forms of energy—bio-fuels, wind and solar, to name a few—are 4 being funded and developed, and will play a growing (5) in the world’s energy supply. But experts say that, even when (6) , alternative energy sources will likely meet only about 30% of the world’s energy needs by 2050.For example, even with (7) investments, such as the $93 million for wind energy development (8) in the American Recovery and Reinvestment Act, important alternative energy sources such as wind and bio-fuels (9) only about 1% of the market today.Energy and sustainability experts say the answer to our future energy needs will likely come from a lot of (10) —both traditional and alternative.A.stableB.solutionsC.significantD.roleE.progressF.marvelousG.includedH.growthI.exactlyJ.consistK.compriseL.competitionsM.combinedN.challengesO.certainly (10)处应填()