Since или for. Урок английского языка

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

2. You haven't smoked sincefor two months.

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

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

5. I haven't slept sincefor 48 hours.

6. We've lived here sincefor seventeen years.

7. You have been watching TV sincefor hours.

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

9. Jane has worked here sincefor two weeks already.

10. These cherry trees have bloomed every spring sincefor 1980.