单词：compulsary
单词：compulsary 相关文章
This is Scientific Americans 60-SecondScience. Im John Matson, got a minute? Say you need a diamond. You could go downto the jeweler, or you could put some carbon deep underground and let it sitfor a couple billion years. Or you could hop in a starsh
Scientific American(八)月
Like a phoenix rising from the ashes, astronomers have found a whole new solar system may be forming in the wake of a star's violent death. This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy wit
国家地理2008年
Like a phoenix rising from the ashes, astronomers have found a whole new solar system may be forming in the wake of a star's violent death. This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with
自然百科2008年
Could these be the neutron stars predicted by Z? astronomers nicknamed them pulsars and immediately set their telescopes searching for further clues about them, just a year later, they found one, in the perfect place to put Z's theory to the test.In
探索与发现2015年