Here are the mistakes identified in each of the sentences:

1. **Sentence 1:** The mistake is in (C) "is looking" - it should be "looks."
2. **Sentence 2:** The mistake is in (B) "but" - it should be "and."
3. **Sentence 3:** The mistake is in (A) "are" - it should be "is."
4. **Sentence 4:** The mistake is in (A) "brought" - it should be "brought."
5. **Sentence 5:** The mistake is in (B) "let them" - it should be "let."
6. **Sentence 6:** The mistake is in (A) "would" - it should be "prefer."
7. **Sentence 7:** The mistake is in (A) "doesn't" - it should be "does."
8. **Sentence 8:** The mistake is in (A) "advised" - it should be "advised me to."
9. **Sentence 9:** The mistake is in (A) "being" - it should be "made."

Feel free to ask if you need further clarification on any of these!