Since или for. Урок английского языка

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

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

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

4. She has been in hospital sincefor Monday.

5. They have been ill sincefor Monday.

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

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

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

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

10. New ideas have been put into practice sincefor he was elected our leader.