Since или for. Урок английского языка

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

2. I haven't slept sincefor 48 hours.

3. They haven't visited us sincefor Christmas.

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

5. Jane has worked here sincefor two weeks already.

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

7. John and Bob have been working on this project sincefor five months already.

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

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

10. Joe and Josephine have been going out together sincefor Valentine's Day.