Since или for. Урок английского языка

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

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

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

4. She has been in hospital sincefor Monday.

5. Jane has worked here sincefor two weeks already.

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

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

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

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

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