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Rho Ophiuchi dark cloud is one of the closest star-forming regions to our own solar system. Located near the constellations Scorpius and Ophiuchus, the nebula is about 407 light years away from Earth. The infrared astronomical satellite, now celebra

发表于:2018-12-05 / 阅读(62) / 评论(0) 分类 国家地理2008年

By Al Pessin Washington 10 September 2007 The American commander in Iraq says the U.S. troop presence there will be reduced by about 2,000 this month, and another 3,500 by the end of the year. But General David Petraeus said he needs most of the 168,

发表于:2019-01-16 / 阅读(95) / 评论(0) 分类 2007年VOA标准英语(九月)

By Al Pessin Washington 08 April 2008 The top U.S. military commander in Iraq and the U.S. ambassador told Congress Tuesday that progress in Iraq is fragile and reversible, and called for continuing U.S. commitment, including an open-ended pause in U

发表于:2019-02-04 / 阅读(48) / 评论(0) 分类 VOA常速英语2008年(四月)

By Al Pessin Pentagon 10 April 2008 In congressional testimony this week, the top U.S. military and civilian officials in Iraq reported what they called real but fragile progress, and urged caution in any discussion of further U.S. troop withdrawals,

发表于:2019-02-05 / 阅读(56) / 评论(0) 分类 VOA常速英语2008年(四月)

The coalition commander in Iraq, General David Petraeus, has left his post after a momentous year and a half, during which he is widely credited with turning around the fight against a variety of insurgent groups. He will now become the overall comm

发表于:2019-02-05 / 阅读(48) / 评论(0) 分类 VOA标准英语2008年(九月)

Transcript for Reference Only --chunshan The infrared astronomical satellite, now celebrating its 25th anniversary, gave us the first all sky view of our dusty infrared universe. Floating above the galactic center is the Rho Ophiuchi Cloud, about 400

发表于:2019-02-26 / 阅读(147) / 评论(0) 分类 自然百科2008年