Stem changing verbs

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Across
  1. 3. O -> U
  2. 5. You REPEATED it
  3. 7. He EATS LUNCH
  4. 9. They already CAME here
  5. 10. I BEG you to finish this crossword faster
  6. 12. Yesterday they SLEPT in
  7. 13. they FLEW yesterday
Down
  1. 1. E -> IE
  2. 2. That guy doesn't THINK. At all.
  3. 4. I CRY when you take this long to finish crossword puzzles
  4. 6. I FOUND it yesterday
  5. 8. When did they DIE?
  6. 11. I just found out that she LIED to me yesterday