Ответ:

  1. My little brother still believes in magic.
  2. What is the reason for the celebration?
  3. Are you afraid of the dark?
  4. Edinburgh is famous for its festival.
  5. The carnival was crowded with visitors.
  6. They got tired of waiting for the band.
  7. She is interested in traditional celebrations.
  8. I was pleased with my performance.

Ответ: 1) in; 2) for; 3) of; 4) for; 5) with; 6) of; 7) in; 8) with.