a binary star that is an intense source of X-rays and is composed of a normal star in close orbit with a white dwarf, neutron star, or black hole
When X Always = 10
Roman numerals are a collection of symbols that make up the number system that was used by the ancient Romans. Today, Roman numerals are more commonly used in titles, to number parts of works, in music theory, and on clock faces. Where do you see Roman numerals most often? The Symbols The Roman numeral system uses only seven symbols: I, V, X, L, C, D, …
The Truth Is In The X-Files
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012