单词：germanium-doped silica fiber
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Plant Self-defense Plants may appear to be helpless in the face of hungry,toothy animals but many plants have evolved interesting systems of self-defense. Coarse meadow grasses are a good example. If you run your finger along a blade of coarse grass,
英语听力文摘 English Digest
Knock, knock. Mr Matthews? What a surprise! Where're your parents? They didn't bring me. I took the bus. Actually they don't even know I'm here. I've brought you a germanium. Geranium. Didn't I say germanium? Yes, you did. In fact, germanium is a che
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AS IT IS 2015-07-14 Silica Sand Mining Worries Communities 美国硅砂矿引发社区担忧 The United States is increasing production of oil and natural gas through a process known as fracking. This process is sometimes called hydraulic fracking be
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By Melinda Smith Washington 18 July 2007 We are going to find out about two studies on breast cancer. One studied whether a diet very high in fiber and low in fat could reduce the risk of recurring breast cancer. Another study focused on women with a
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RACHEL MARTIN, HOST: The Food and Drug Administration is set to decide soon on a matter that could help you rethink fiber. Yeah, we're talking about fiber. We're told to eat a whole lot more of it. It's good for us, right? But what exactly counts as
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AILSA CHANG, HOST: Despite mounting evidence and a stream of dire warnings, federal regulators and mining companies failed to protect coal miners from toxic dust. MARY LOUISE KELLY, HOST: NPR and the PBS series Frontline spent more than a year lookin
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