21、_____ well prepared you are , you still need a lot of luck in mountain climbing．

A．However            B．Whatever            C．No matter           D．Although

20、For many cities in the world, there is no room to spread our further, ____ New York is an example．

A．for which        B．in which          C．of which           D．from which

19、Thank you for all your hard work last week．I don’t think we ______ it without you．

A．can manage                                                B．could have managed

C．could manage                                             D．can have managed

18、—They are quiet, aren’t they?

—Yes．They are accustomed ______ at meals．

A．to talk           B．to not talk          C．to talking         D．to not talking

17、The English spoken in the United States is only slightly different from ___ spoken in England．

A．which            B．what            C．that           D．the one

16、一Will somebody go and get Dr．Smith？

一He’s already been        ．

A．a(chǎn)sked for        B．sent for        C．looked for          D．called for

15、______the workshops, the executives had a talk with the workers．

A．Inspected                                                  B．Inspecting

C．Having inspected                                        D．Having been inspected

14、____on his novel, the author decided to adapt it into a play．

A．Basing          B．Based           C．To base          D．Being based

13、The evidence has ______ the first witness's story．

A．confused       B．a(chǎn)ccumulate       C．confirmed          D．a(chǎn)ttached

12、The newly discovered star was named       a Chinese astronomer      honour of his contributions to astronomy．

A．for; in            B．a(chǎn)fter; for         C．a(chǎn)s; in          D．a(chǎn)fter; in