1. a yellow apple
2. yellow apples
3. a red book
4. red books
5. a green pencil
6. green pencils
7. a black cat
8. black cats
9. a blue rubber
10. blue rubbers
11. a white whale
12. white whales
13. a gray goat
14. gray goats
15. an orange fox
16. a pink bag
17. a brown ruler
18. a purple pen
19. a black dog