21、 In order to search for the escaped prisoner, the police decided to question _____ comes along the road.

A．who    B．whom        C．whoever         D．whomever

20、

If something that requires imagination needs _____, a robot is useless.

       A．being done           B．to do                   C．be done               D．doing

19、In 1800, a group of adventurers set out on their exploring trip. Five days later, they came to _______ is now known as Quebec.

           A．what               B．which                 C．the place             D．where

18、Just watch carefully now. I’ll show you one of the most remarkable photographs ______.

       A．having ever been taken                         B．had ever been taken

       C．ever being taken                                  D．ever taken

17、At parties, girls like to help themselves to ice cream and candies rather than wait ____________.

       A．to serve                                              B．to be served           

       C．served                                                D．being served

16、Sandy could do nothing but ______ to his teacher that he was wrong.

       A．admitting            B．admitted        C．admit       D．to admit

15、The news that volunteer workers will go to homes for the aged ______ now.

       A．is being talked about                             B．are being talked about

       C．is being talked                                      D．are being talked

14、Her appearance has changed a lot after the cosmetic surgery and I ___ not recognize her.

    A．must          B．can               C．need             D．will

13、---- Was Tom there when you arrived?

---- Yes, but he _____ home soon afterwards.

       A．had gone             B．has gone              C．is going               D．went

12、In fact, many of our guests ask for accommodations here _____they come.

       A．at time                B．first time             C．for the first time                   D．each time