Too high house prices can be brought under control, ________ the authorities introduce a series of regulatory policies.
| A．even if | B．as if | C．so that | D．provided that |
31. ________was difficult to save 
the places and buildings _____destroying their old beauty.
| A．That…unless | B．This…except | C．It…without | D．There … except for |
30. If we had followed his suggestion, we could have done the work better with _______money and ______people.
| A．less…fewer | B．fewer…less | C．little…fewer | D．less…few |
29. I won’t listen to the new CD unless I ______my homework.
| A．will finish | B．shall finish | C．finish | D．finished |
28. Think after you read ____.
| A．which words do you need to look up | B．you need to look up which words |
| C．which words need you look up | D．which words you need to look up |
27. Great changes _______in our city in the past twenty years.
| A．have been taken place | B．have taken place |
| C．took place | D．were taken place |