7. They started working in that factory in 2001.

8. He has worked for this company for 5 years.

9. They have lived here for 10 years.

10. Lan has learnt French since 2000.

12. They have checked the machines for 2 hours.

14. She has cooked the soup for half an hour.

15. We have done the test for an hour.

16. Jack has planted flowers for 3 hours. 

18. Nam has learnt English since 1998.

19. Bang has raised birds since May.

20. Van has collected stamps since Sunday.

21. Hang has listened to music since 8 o'clock.

22. Mai has made a dress since Saturday.

23. He has watered the vegetables since 9.

24. Khanh has played computer games since 2002.

27. Minh has sold lottery tickets since June.

28. It has rained for an hour.

$\text{7 They started working in that factory in 2001.}$

$\text{8 He has worked for this company for 5 years.}$

$\text{9 They have lived here for 10 years.}$

$\text{10 Lan has learned French since 2000.}$

$\text{12 They have checked the machines for 2 hours.}$

$\text{14 She has cooked the soup for half an hour.}$ 

$\text{15 We have done the test for an hour.}$

$\text{16 Jack has planted flowers for 3 hours.}$

$\text{18 Nam has learned English since 1998.}$

$\text{19 Bang has raised birds since May.}$

$\text{20 Van has collected stamps since Sunday.}$

$\text{21 Hang has listened to music since 8 o'clock.}$

$\text{22 Mai has made a dress since Saturday.}$

$\text{23 He has watered the vegetables since nine.}$

$\text{24 Khanh has played computer games since 2002.}$

$\text{27 Minh has sold lottery tickets since June.}$

$\text{28 It has rained for an hour.}$