Ответ:
1. Are they economists?
They are not economists.
2. Is it a pencil?
It isn't a pencil.
3. Is she a teacher?
She is not a teacher.
5. Are you from Canada?
You are not from Canada.
4. Is it an orange?
It is not an orange.
6. Is Mark thirteen years old?
Mark is not thirteen years old.
7. Are Jill and Sue sisters?
Jill and Sue are not sisters.
8. Is his name Mark?
His name is not Mark.
9. Is Sally my friend?
Sally is not my friend.
10. Are they in the garden?
They are not in the garden.
Объяснение: