Exact(1)
It probably consists of unknown elementary particles, and it's much more prevalent than the normal matter from which stars, planets, and people are made.
Similar(7)
Cancer of unknown primary.
carcinomas of unknown primary.
These are invisible particles -- perhaps unknown elementary particles left over from the Big Bang -- that move slowly, rarely interact with other matter and are unlike the ingredients of stars, planets and people.
SMKA/GRC relates unknown elementary rate constants to known ARL kinetic constants.
By weight it is 4percentt atoms and 22percentt so-called dark matter of unknown identity — perhaps elementary particles that will be discovered at the Large Hadron Collider starting up outside Geneva this year.
Sources: 1. of unknown origin.
It had photographs of unknown….
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