Ответ:

3***

1)to

2)in

3)to

4)to

5)in

6)to

4***

1) how long have you known him?

2)I've been working here for three years now

3)I've never been to Paris before

4)I've been in London for three weeks now

5)how long has he been teaching Physics?

6)how long have they been married?

7)he has been living here for 12 years

8)has she lived there long?

9)Have you been in New York long?

10)We've been married since last year