6. 1) is

2) in

3) find

4) on

5) does

6) keep (но это не точно)

7) at

7. 1) - с

2) - d

3) - е

4) - b

5) - a

8. I'm sorry to have keep you waiting. He may not be in his office right now, He is at work today. May you find him for me? He cant pick up the phone at the moment. Stay on the line. One minute.