Answer: I think it's asking you to find words in the song that change the mood, and explain why they change the mood.
Answer:
C
Explanation:
Being that they were unnoticed, sounds like it's not a major key detail.
Answer:
The students passed the exam last week.
Explanation:
Because the second sentence says the students WERE passed the exam last week and <em>were</em> doesn't need to be in there. Therefore it is not correct.
I would go with the first one makes,more,sence