Since или for. Урок английского языка

1. You haven't smoked sincefor two months.

2. We've lived here sincefor seventeen years.

3. I haven't worked sincefor a mounth.

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

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

6. They haven't visited us sincefor Christmas.

7. They have been ill sincefor Monday.

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

9. He worked at that company sincefor ten years before he retired.

10. They've been teaching here sincefor quite a long time.