单词：cesium brcarbonate
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20本英文音韵童谣小书（文本+音频）
今天要讲的三个习惯用语都是和零碎的小东西有关。他们之间的区别只是使用的场合不同，或者是来源不一，用法相近。现在我们就分别为各位讲解这三个习惯用语。他们是：odds and ends, knic
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[00:06.37]The United States has a new official clock. [00:10.95]The clock began operating late last year in the American city of Boulder,Colorado. [00:18.39]Experts say the new clock is so exact that it will neither gain nor lose so much as one secon
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Youve given some thought to oxygen, carbon, uranium. But youve probably never mused about the element ytterbium, symbol Yb. A new study by scientists at the National Institute of Standards and Technology, or NIST, says that ytterbium could find a rol
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SANYA, Hainan, Dec. 4 (Xinhua) -- The five BRICS nations intend to focus and work together on developing alternative energy sources. When Bu Xiaolin, vice governor of China's coal-rich Inner Mongolia autonomous region, spoke over the weekend in front
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日常生活中，意外伤害很难避免。如果我们不及时救治或者操作不当的话，很可能会对自身或者他人的身体造成伤害，所以，掌握一些急救常识非常必要。下面我们来看一段关于学习急救的对
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