Решение:
- My son's son is my grandson.
- My dad's brother is my uncle.
- My mum's father and mother are my grandparents.
- My parents' daughter is my sister.
- My father's father is my grandfather.
- My father's sister's children are my cousins.
- My brother's daughter is my niece.
- My daughter's daughter is my granddaughter.
- My sister's son is my nephew.
Ответ: 1. grandson, 2. uncle, 3. grandparents, 4. sister, 5. grandfather, 6. cousins, 7. niece, 8. granddaughter, 9. nephew.