challenge word's crossword Z/F

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Across
  1. 2. the middle of something
  2. 5. after the expected
  3. 6. to see something
  4. 8. something in your body that pumps blood
  5. 9. to see something and then it vanishes
Down
  1. 1. to gain knowledge
  2. 3. a sentence connector
  3. 4. 60 seconds
  4. 7. to choose between two things