Gerund or infinitive?

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Across
  1. 2. keep away from
  2. 3. decide or arrange in advance
  3. 4. the opposite of like
  4. 6. begin
  5. 8. related to memories
  6. 9. feel sad over something you have done
  7. 11. require, expressing necessity
  8. 12. like
Down
  1. 1. think carefully about something
  2. 3. perform or exercise a skill
  3. 5. fail to remember
  4. 7. make an attempt or effort
  5. 10. the opposite of start