a)
3. Don't
4. Doesn't
6. Doesn't
7. Don't
b)
1) Bless doesn't help her mother
2)My friend doesn't play the piano
3)We don't listen to music
4)You don't make a lot of mistakes
5)The farmer doesn't work in the field
6)The small boy does ride a bike
7)He doesn't look at the pictures in the book
8)The workman doesn't paint the house
9)Richard and Henry don't swim in the river in summer
10) John doesn't go to school by tram
11)She doesn't get bp at eight o'clock
12)He doesn't have tea for breakfast
13)She usually doesn't have dinner at two o'clock
14)Peter doesn't live in London