Since или for. Урок английского языка

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

2. I haven't met Jill sincefor the end of the school.

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

4. Jane hasn't been back to Hungary sincefor last year.

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

6. Dinosaurs have been extinct sincefor over 60 million years.

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

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