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2007年VOA标准英语-NASA Mission to Seek Polar Lights' Energy Sourc

By David McAlary Washington 18 February 2007 The U.S. space agency NASA has launched five satellites - the most ever from one rocket - to locate the source of energy in Earth's magnetic field that triggers the colorful, dancing auroras over the north

发表于:2019-01-12 / 阅读(106) / 评论(0) 分类 2007年VOA标准英语（二月）
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