17. I should very much like to have gone to the party,but I(      ).

  A. am not invited                   B. am not being invited

  C. shall not be invited                 D. was not invited

18. I'll buy one (      ) it costs.

  A. whichever              B. however

  C. whateve r                D. whenever

19. Nowhere else in the world (      ) more attractive scenery than in Switzerland.

  A. you can find          B. in found

  C. can you find          D. had been found

20. (      ),she went back to her room.

  A. There was no cause for alarm

  B. Being no cause for alarm

  C. Without having cause for alarm

  D. There being no cause for alarm

21. This is the second time she (      ) improvement in that equipment.

  A. had made               B. made

  C. is making                D. has made

22. She found one excuse after another to postpone (      ) to the doctor.

  A. to go                B. going

  C. to have gone           D. having gone

23. The further this process is allowed to go,(      ) it will be to reverse it.

  A. the more difficult                  B. the more easier

  C. the more easy                   D. more difficult

24. This is the refrigerator (      ) we have had so much trouble.

  A. with which             B. of which

  C. at which               D. to which