Prefixes: super, sub & inter

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Across
  1. 5. Having special powers.
  2. 6. A walkway under a road.
  3. 8. Hugely famous.
  4. 9. Something involving two or more countries.
Down
  1. 1. A heading given to a section of writing.
  2. 2. Seeing ghosts.
  3. 3. Questions and answers
  4. 4. Self-service shop.
  5. 7. Vehicle that travels below the waves.