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. We haven't seen Mary sincefor the party.

4. They have been ill sincefor Monday.

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

6. I haven't talked to him sincefor last week.

7. He's been working in the field sincefor early this morning.

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

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

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