Since или for. Урок английского языка

1. You haven't smoked sincefor two months.

2. We've been friends with Fred sincefor decades.

3. I haven't worked sincefor a mounth.

4. We've been together only sincefor a few days.

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

6. She has been in hospital sincefor Monday.

7. He hasn't played the piano sincefor he was a boy.

8. Jane has worked here sincefor two weeks already.

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

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