Ответ:

EX 3

1. This is the robot which cleans floors.

2. She is a woman who designs gadgets.

3. I bought a clock which plays music.

4. That's the shop where I bought my gloves.

5. Is that your friend who works for Microsoft?

6. Have you got a mouse that you don't need?

7. This is the town where Maria Curie was born.

EX 4

1. It's a thing which you use to charge a phone. CHARGER

2. It's a place where you put USB gadgets. USB PORT

3. This is a person who collects things. COLLECTOR

4. It's a place where you can read information online. WEBSITE

5. It's a thing which takes photos. CAMERA

6. This is a person who works in a laboratory. SCIENTIST

EX 5

1. who

2. where

3. which

4. where

5. who

6. which