16. They are going to have the serviceman ___________ an electric fan in the office tomorrow.

A. install                           B. to install

C. to be installed                      D. installed

17. Since both he and I work in the same hospital, I can hardly avoid _________ him.

A. being met       B. meeting          C. to be met        D. to meet

18. The indoor swimming pool seems to be a great deal more luxurious than _____________.

A. is necessary                        B. being necessary

C. to be necessary                       D. it is necessary

19. What a lovely party! It’s worth ___________ all my life.

A. remembering                         B. to remember

C. to be remembered                     D. being remembered

20. Contrast may make something appear more beautiful than it is when ___________ alone.

A. seen                                B. is seen

C. to be seen                           D. having been seen