Since или for. Урок английского языка

1. You haven't smoked sincefor two months.

2. My boss has been away sincefor half a day only.

3. We haven't seen Mary sincefor the party.

4. I've read two books sincefor the weekend.

5. You have been watching TV sincefor hours.

6. Dinosaurs have been extinct sincefor over 60 million years.

7. I haven't talked to him sincefor last week.

8. They have been raising horses and cows on their farm sincefor many years.

9. John and Bob have been working on this project sincefor five months already.

10. They've been in love sincefor three weeks.