Answer: I think it's adverb but it could be adjective.
Answer: when you think something is a liking verb, putting in the word 'is' in for it. if the sentence doesn't make sense, then its not a linking verb. if it does, it probably is a linking verb.
Explanation:
1. True
2. True.
3. True.
4. b.
5. a.
6. c
7. b
8. a
9. b.
10. c
11. b.
12. c.
13. a.
14. Pathos; credibility of a dentist.
15. ethos; emotion of sad dogs.
Hope it helps! :)