mono-/uni-/bi-

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Across
  1. 8. glasses
  2. 9. travel by sitting INSIDE one wheel
  3. 10. mythical creature
  4. 11. boring
  5. 12. Milky Way
  6. 13. ride with two wheels
Down
  1. 1. speech
  2. 2. travel by sitting ON one wheel
  3. 3. Fluent in English and French, for example
  4. 4. train
  5. 5. same outfit
  6. 6. strong arms
  7. 7. all the green properties, for example
  8. 8. January, March, May...
  9. 10. altogether