Here are the identified mistakes and corrections:

26. **Mistake**: C ("because")
**Correction**: "Not many people went to see the film, despite good reviews from critics."

27. **Mistake**: A ("watch")
**Correction**: "Did you watch the cartoon last night?" (no correction needed here since the phrasing is appropriate; the response should be adjusted to "No, I didn't.")

28. **Mistake**: A ("used to go")
**Correction**: "Did you use to go to school on foot?"

29. **Mistake**: C ("riding")
**Correction**: "It takes me 30 minutes to ride home from school."

30. **Mistake**: C ("really")
**Correction**: "We find 'Avenger' very exciting."