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On December 25, 2000, many people across North America received a rare Christmas treat when the moon passed in front of the sun resulting in a partial solar eclipse. Solar eclipses occur when the moon passes between the Earth and the sun, and the moo
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by Jason Marshall Weve now talked about three methods for calculating average values: the mean, median, and mode (affectionately known as the three Ms). So, are we done? Is that everything we could ever want to know about interpreting average values?
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This is Scientific American's 60-Second Science. I'm Steve Mirsky. Got a minute? The 2011 Nobel Prize in chemistry goes to Daniel Schechtman of the TechnionIsrael Institute of Technology in Haifa. Schechtman discovered what are called quasicrystals.
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AS IT IS 2016-09-02 Ring of Fire Eclipse Passes Over Africa People in parts of Africa witnessed a ring of fire in the sky Thursday, created by the moon passing between the Earth and the sun. The solar event is called an annular eclipse. A total solar
2016年VOA慢速英语(九)月
An annular solar eclipse is seen formed over the sky of Burma's ancient historic city of Bagan, 15 Jan 2010 Holly Gilbert, an astrophysicist at NASA, explains the science behind the spectacle of the sun's disappearance. So during a total solar eclips
VOA标准英语2010年(七)月