Since или for. Урок английского языка

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

2. I haven't slept sincefor 48 hours.

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

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

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

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

7. You have been watching TV sincefor hours.

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

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

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