Mono base crossword

123456789101112131415161718192021
Across
  1. 3. using only one colour
  2. 5. train running on a single rail
  3. 7. voice with one unchanging pitch
  4. 8. detailed study of one subject
  5. 9. single eyepiece for one eye
  6. 10. system ruled by one leader
  7. 13. word with just one syllable
  8. 15. obsession with one idea
  9. 17. exclusive control by one seller
  10. 18. long speech by one speaker
  11. 19. marriage to one person
  12. 21. compound with one oxygen atom
Down
  1. 1. single ruler of a kingdom
  2. 2. man living a solitary religious life
  3. 3. massive structure made of one stone
  4. 4. single unit that can join to form polymers
  5. 5. speaking only one language
  6. 6. design made from one set of initials
  7. 11. sameness or lack of variety (one repeated thing)
  8. 12. to do one task at a time
  9. 14. having one point of focus
  10. 16. seasonal wind pattern (originally meaning a single season)
  11. 18. sound coming from one channel
  12. 19. print or design made as a single unique piece
  13. 20. relating to monks living a single, simple life