单词：three-level laser material
单词：three-level laser material 相关文章
Its the material at the tip of a pencil and it has the potential to revolutionize our lives. A study from Columbia University has shown that graphene is the strongest material in the world. In fact , it is much tougher than diamonds and 300 times str
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1.audit 审计 2.attestation 鉴证 3.credibility 可信赖程度 4.audit of financial statements 财务报表审计 5.agreed-upon procedures 执行商定程序 6.high levels of assurance 高水平保证 7.compilation 编制 8.reliability 可靠性 9
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BOB DOUGHTY: This is SCIENCE IN THE NEWS in VOA Special English. Im Bob Doughty. CHRISTOPHER CRUISE: And Im Christopher Cruise. Today we tell about two recent inventions that have helped to save lives. We will also tell about the people who developed
2011年VOA慢速英语(三)月
This podcast seems like a very simple one; what could I possibly have to teach about the stairs? Well, there are many kinds of stairs in a home. You have the steps leading up to the front door, or between one room and another. Sometimes a room can be
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There is a new substance that is harder than diamond. It's called Q-carbon, and it was created by researchers at North Carolina State University. 北卡罗莱纳州立大学的研究人员研发出一种名为Q-碳的新物质，其硬度比钻石还高
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There is a new substance that is harder than diamond. It's called Q-carbon, and it was created by researchers at North Carolina State University. 北卡罗莱纳州立大学的研究人员研发出一种名为Q-碳的新物质，其硬度比钻石还高
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