Is oxygen the only gas ___ helps fire burn?

   A. that      B. 不填            C. which           D. it

The factory ___ his mother works is in the east of the city.

A. That         B. which        C. on which     D. where

Do you know the girl to ____ your class teacher is talking?

  A. that        B. whom        C. who        D. which

I can think of many cases _____ students obviously knew a lot of English words and expressions but couldn’t write a good essay.

  A. what      B. which        C. where      D. when

The film brought the hours back to me_____ I was taken good care of in that faraway village.

     A. until      B. that      C. when        D. where

American women usually identify their best friend as someone _____ they can talk frequently.

     A. who              B. as         C. about which              D. with whom

There are two buildings, ____ stands nearly a hundred feet high.

  A. the larger            B. the larger of them

  C. the larger one that      D. the larger of which   

The gentleman _____ you told me yesterday proved to be a thief.

    A. who           B. about whom    C. whom             D. with whom

The teacher discussed with Jim, _____ problem was poor study habits.

   A. one of which      B. one of whose    C. whose           D. which

This is the book _____ I paid ten yuan.

        A. for which     B. for that   C. which          D. off which