The key answer of exercise 4

a)

1. on
2. in
3. under

b)

Picture 1

• The charger is in the bag.
• The keys are under the desk.
• The scissors are on the book.
• The wallet is on the desk.
• The glasses are on the book.
• The laptop is on the chair.
• The umbrella is under the chair.

Picture 2

• The file is under the desk.
• The headphones are in the bag.
• The magazine is under the bag.
• The phone is on the chair.
• The photo is on the desk.
• The tissues are in the bag.
• The watch is on the book.