托福阅读素材（七）

　　The most fitting end for the carbon that human beings have tapped from the Earth, in coal, oil, and gas, would be to send it back where it came from—into coal seams, old oil and gas fields, or deep, porous rock formations. Not only would that keep the carbon out of the atmosphere, but the high-pressure injection could also be used to chase the last drops of oil or gas out of a depleted field.

　　In fact geologic sequestration, as it's called, is already under way. One field in the North Sea, for example, yields gas that is heavily contaminated with natural carbon dioxide. So before shipping the gas, the Norwegian oil company Statoil filters out the carbon dioxide and injects it into a sandstone formation half a mile (0.8 kilometer) below the seafloor. The U.S. Department of Energy plans to start its own test project, which would drill a 10,000-foot (3,000-meter) well in West Virginia and pump carbon dioxide into the deep rock.

　　No one knows yet how well such schemes might work in the long run. Tapped-out oil and gas fields are, by nature, full of man-made holes that might leak the carbon dioxide. Even if the stored gas didn't leak straight to the surface, it might seep into groundwater supplies. But the North Sea project seems to be working well eight years after it began. Seismic images that offer views beneath the ocean floor show that the thick layer of clay capping the sandstone is effectively sealing in the 6 million tons (5.4 million metric tons) of carbon dioxide injected so far.

　　That's encouraging news for researchers who are working on schemes that would allow humanity to keep burning fossil fuels without dire consequences for climate. Researchers at Princeton, for example, are exploring a technology that would take the carbon out of coal.

　　In a multistep process coal would react with oxygen and steam to make pure hydrogen, plus a stream of waste gases. The hydrogen could be burned to produce electricity or distributed to gas stations where hydrogen-powered cars—emitting nothing but water vapor—could fuel up. The waste, mostly carbon dioxide but also contaminants that coal-burning plants now emit, such as sulfur and mercury, would be buried. The scheme, says Princeton energy analyst Robert Williams, "could make coal as clean as renewable energy, and you can exploit the low cost of coal."

　　Or maybe the future lies in fields of solar panels, armies of giant wind turbines, or a new generation of safe nuclear reactors. No one knows, but that gauge in Wofsy's shack tells us that we don't have long to dither. The trees are doing their best, but year by year the flickering red number is climbing.

五、托福阅读素材之微笑的力量

　　The hidden power of smiling

　　0:11

　　When I was a child, I always wanted to be a superhero. I wanted to save the world and make everyone happy. But I knew that I'd need superpowers to make my dreams come true. So I used to embark on these imaginary journeys to find intergalactic objects from planet Krypton, which was a lot of fun, but didn't yield much result. When I grew up and realized that science fiction was not a good source for superpowers, I decided instead to embark on a journey of real science, to find a more useful truth.

　　0:41

　　I started my journey in California, with a UC Berkeley 30-year longitudinal study that examined the photos of students in an old yearbook, and tried to measure their success and well-being throughout their life. By measuring the students' smiles, researchers were able to predict how fulfilling and long-lasting a subject's marriage would be,

　　1:03

　　(Laughter)

　　1:04

　　how well she would score on standardized tests of well-being, and how inspiring she would be to others. In another yearbook, I stumbled upon Barry Obama's picture. When I first saw his picture, I thought that his superpowers came from his super collar.

　　1:20

　　(Laughter)

　　1:21

　　But now I know it was all in his smile.

　　1:24

　　Another aha! moment came from a 2010 Wayne State University research project that looked into pre-1950s baseball cards of Major League players. The researchers found that the span of a player's smilecould actually predict the span of his life. Players who didn't smile in their pictures lived an average of only 72.9 years, where players with beaming smiles lived an average of almost 80 years.

　　1:52

　　(Laughter)