Since или for. Урок английского языка

1. You haven't smoked sincefor two months.

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

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

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

5. She has been in hospital sincefor Monday.

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

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

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