6. 1) had worked
2) works
3) is working
4) has been working
7. 1) was used
2) got used
3) used
4) uses
8. 1) was working
2) was worked
3) has been working
4) had worked
9. 1) had been met
2) met
3) was meeting
4) was met
10. 1) highly respect
2) has highly respected
3) highly respects
4) is highly respected