21. C -  A new hospital has been built near the airport

22. A - Complaints should be sent to the head office.

23. A - The meeting had to be postponed because of illness.

24. B - Your car might be stolen.

25. D - Next year’s congress is going to be held in San Francisco?

26. A - The date of the meeting has been changed. 

27. B - I was told by Brian that he had been attacked in the street

`text{21. C  A new hospital has been built near the airport}`

`text{22. A Complaints should be sent to the head office}`

`text{23. A The meeting had to be postponed because of illness}`

`text{24. B Your car might be stolen}`

`text{25. D Next year’s congress is going to be held in San Francisco?}`

`text{26. A The date of the meeting has been changed}`

`text{27. B I was told by Brian that he had been attacked in the street}`