三、 A decade ago, James A. Thomson was the first to isolate human embryonic stem cells. Last week, he announced one of the great scientific breakthroughs since the discovery of DNA: an embryo-free way to produce genetically matched stem cells.        Even a scientist who cares not a whit about the morality of embryo destruction will adopt this technique because it is so simple and powerful.        The embryonic stem cell debate is over. This allows a bit of reflection on the storm that has raged ever since the August 2001 announcement of President Bush's stem cell policy. The verdict is clear: Rarely has a president — so vilified for a moral stance — been so thoroughly vindicated.

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2025/02/20

十年前，詹姆斯‧湯姆森（James A....

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四、 Hydrocarbon fuels (chiefly coal, oil and natural gas) were first used to create energy at the dawn of the Industrial Revolution, as mankind began to run short of traditional fuels like wood and whale oil. The new fuels contained more latent energy than any previously discovered, but they also came with a flaw: the carbon emissions that are an unavoidable by-product of their combustion. These gases build up in the planet’s atmosphere, where they act like the panes of glass on a greenhouse, allowing the sun’s warmth in but not back out. As heat that would ordinarily radiate off into space is instead reflected once again toward the planet’s surface, temperatures begin to rise and the globe begins to warm. Two of the sharpest spears created by global warming — flooding and drought — account for more than half the world’s deaths from natural disaster. Nations whose land lies close to sea level, like the Netherlands, Bangladesh and Indonesia, are at great risk, as are locations where natural barriers against water have been degraded by man. Scientists believe that Hurricane Katrina would have packed a far less devastating punch if the wetlands that buffer New Orleans from the Gulf of Mexico had not been removed by imprudent levee-building and oil and gas development.

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