1. on
2. on
3. behind
4. next to
5. next to
6. on
7. on
8. under
Where is the pillow? It's on the bed.
Where are two (или можно the вместо two) windows? They're behind the bed.
Where is the lamp? It's next to the bed.
Where is the chair? It's next to the desk.
Where are some (или the) magazines? They're on the desk.
Where is some (или the) pictures and the poster? It's on the wall.
Where is the bedside table? It's under the poster.