1) posters

2) walls

3) windows

4) boards

5) DVD players

6) computers

7) door shelves

8) plants

9) books

10) bins

11) CD players

12) cupboards

13) dictionaries

14) desks

15) rulers

16) pencils

17) pens

18) watches

19) books

20) chairs

21) bags

posters, walls, windows, boards, DVD players, computers, door shelves, plants, books, bins, CD players, cupboards (пишется слитно), dictionaries(там ошибка),desks, rulers (там ошибка), pencils, pens, watches, books,chairs, bags.