25、－I’m so tired, working all morning on the farm.

－Why not take a rest, then?

－__________.

A．Because I can’t afford it                              B．Maybe I should

C．I don’t know                                              D．Sorry, I can’t tell it

24、New technology ____ to make sure that the cars, taxis, buses and trains we use _____ the air.

A．is used; not pollute                                      B．has used; is not polluted

C．is being used; do not pollute                         D．has been used; to pollute

23、－Do you mind if Martin join in your work?

－Yes, I do. I ‘ll be glad to work with _________ Martin.

A．anybody but     B．somebody but   C．nobody but      D．all besides

22、________ villagers on that island have been living in ________ peace for years with one another.

A．The; /       B．/; the C．The; a      D．The; the

21、－All of us had a good time in the picnic last Sunday. Pity you weren’t there.

－I really _______ come but I was looking after my mother in hospital.

A．must        B．ought to    C．need have        D．should have

20、In the botanic garden we can find a(an) ___ of plants that range from tall trees to small flowers.

A．species     B．group       C．amount     D．variety

19、－Take this medicine three times a day, Tom.

－Do I have to take it? It __________ so terrible.

A．is tasting          B．is tasted    C．tastes       D．has tasted

18、The professor could hardly find enough reasons ____ his arguments in favor of the new theory.

A．to be based on                                            B．to base on           

C．which to base on                                        D．on which to base

17、She __ to bed when the earthquake suddenly started. That was why she was just in her bed clothes.

A．was about to go       B．went         C．did go       D．would go