ex 1
2. behind
3. in
4. on
5. next to
6. in front of
ex 3
2. Where's the white rubber? It's in the pencil-сase.
3. Where's the red pencil? It's in front of the pencil-сase.
4. Where's the board? It's on the wall.
5. Where's the books? It's on the desk.
6. Where's the laptop? It's on the desk.
7. Where's the bag? It's in front of the desk.