Since или for. Урок английского языка

1. Jane hasn't been to America sincefor 1981.

2. I haven't met Jill sincefor the end of the school.

3. I haven't slept sincefor 48 hours.

4. We've lived here sincefor seventeen years.

5. I haven't worked sincefor a mounth.

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

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

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

9. Jane has worked here sincefor two weeks already.

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