Past tense word puzzle

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Across
  1. 3. think
  2. 5. hit
  3. 7. fall
  4. 9. see
  5. 10. go
  6. 11. walk
  7. 13. ask
  8. 15. run
  9. 16. have
  10. 17. is
Down
  1. 1. follow
  2. 2. cry
  3. 4. disappear
  4. 6. sit
  5. 8. look
  6. 12. sing
  7. 14. know
  8. 18. say