Answer:
- inquisitive
- irritating
- integrity
- ensuing
- harmonize
- disarm
- melancholy
- transaction
Step-by-step explanation:
(1) inquisitive -- descriptive of someone who asks a lot of questions
(2) Irritating -- echos "annoying"
(3) integrity -- a noun naming the characteristic of performing an obligation even when it is difficult
(4) ensuing -- time-related, describing something that follows
(5) harmonize -- merging different views or creating consistency
(6) disarm -- reduce hostility
(7) melancholy -- echos "unhappy"
(8) transaction -- seems like the wrong word, but it's the only one left. I might prefer a word that refers to a duration or a contract or assignment, not one that implies some sort of specific action or exchange.