Since или for. Урок английского языка

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

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

3. They haven't visited us sincefor Christmas.

4. They have been ill sincefor Monday.

5. Jane has worked here sincefor two weeks already.

6. I haven't talked to him sincefor last week.

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 in love sincefor three weeks.

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