The key answer of exercise 2

a)

1. a
2. b

c)

1. an American car; American cars
2. an expensive watch; expensive watches
3. a big house; big houses
4. a tall man; tall men
5. a long book; long books
6. a new phone; new phones
7. a good friend; good friends
8. a beautiful woman; beautiful women
9. a small child; small children