IV/

26. A 

27.  A

28. C

29. C

30. B

V/ 

31. C

32. A
33. C

34. B

35. A

VI/ 

36. There didn't used to be a sport center here. 

37. You should leave the lights off when you leave the classroom.

38. He suggested that we should do something to protect the environment. 

39. I used to be taken to school when i was small by my parents.

40. She hasn't wore that uniform since she left the secondary school.

$IV/$

$26. a$

$27.  a$

$28. c$

$29. c$

$30. b$

$V/ $

$31. c$

$32. a$
$33. c$

$34. b$

$35. a$

$VI/ $

$36. There$ $didn't$ $used$ $to$ $be$ $a$ $sport$ $center$ $here. $

$37. You$ $should$ $leave$ $the$ $lights$ $off$ $when$ $you$ $leave$ $the$ $classroom.$

$38. He$ $suggested$ $that$ $we$ $should$ $do$ $something$ $to$ $protect$ $the$ $environment. $

$39. I$ $used$ $to$ $be$ $taken$ $to$ $school$ $when$ $i$ $was$ $small$ $by$ $my$ $parents.$

$40. She$ $hasn't$ $wore$ $that$ $uniform$ $since$ $she$ $left$ $the$ $secondary$ $school.$