The key answer of exercise 3

a)

1. see → to notice something using your eyes, deliberately or by chance, for a long or a short time; look at → usually for a short time deliberately; watch → for a long time deliberately, paying attention to what is happening (e.g. a TV programme)
2. listen to → deliberately; hear → probably by chance
3. touch → for one moment, usually with your hands; hold → for a long time, in your hands or arms

b)

1. hold
2. seen
3. hear
4. touch
5. looking at
6. listen to
7. watch