Question

Question was provided via image upload.

Explanation:

1. For the first sentence, "song" fits as it's related to music class.
2. "Dr. Green" is a proper noun for a doctor, so it fits for taking the cat to see a doctor.
3. "Saturn" is the planet with rings, so it's the answer.
4. "doctor" is a common noun for the person you see when sick.
5. "poem" fits as it's related to a poetry contest.
6. "planet" is the general term, and Mars is a planet.
7. "Where the Sidewalk Ends" is a book title, so it's the answer.
8. "Twinkle, Twinkle Little Star" is a song to sing before bed.

Answer:

1. song
2. Dr. Green
3. Saturn
4. doctor
5. poem
6. planet
7. Where the Sidewalk Ends
8. "Twinkle, Twinkle Little Star"