Roman Numerals

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Across
  1. 1. C
  2. 4. USA celebrated this in 1976
  3. 6. LXIV
  4. 8. literal translation: seventh month
  5. 10. English meaning of proton
  6. 11. Latin cardinal number for one
  7. 13. one thousand meters
  8. 18. belief in one god
  9. 19. solid with four sides
  10. 20. If you are a quintuplet you have ___ siblings your age
Down
  1. 2. Greek cardinal number for nine
  2. 3. they derived the arithmetic representation of zero
  3. 5. a thousand years
  4. 7. X
  5. 9. one-sixty-fourth note
  6. 12. XIX
  7. 14. cephalopod with eight legs
  8. 15. English meaning: both
  9. 16. red, blue, and yellow are ___ colors
  10. 17. Latin cardinal number for two