Observations of a distant galaxy cluster collision reveal a core of invisible matter devoid of glittering galaxies-something that is hard to explain by current theories.
Resource Construction is the core of the Distant Education; high-efficient resource management can improve resource service efficiency and promote teaching better.
资源建设是远程教育的核心，高效的资源管理能提高资源使用效率，更好的促进教学开展。
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While they have been detected in many distant star clusters, and among nearby stars, they never have been seen inside the core of our galaxy.