17. This museum is ______ you visited the other day.

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

16. This is the museum ______ we saw an exhibition the other day.

A. that 　B. which 　C. where 　 D. in that

15. Air, ______ we breathe every day, is around us all the time.　

A. that 　　B. / 　C. which 　D. it

14. Is oxygen the only gas ______ helps fire burn?

A. that　　 B. / 　C. which　　 D. what

13. This is the biggest lab ______ we have ever built in our university.

A. which 　B. what 　C. that 　D. where

12. I can tell you ______ he told me last week.　 A. all which 　　B. all what 　　　

C. that all 　　　　　 D. all that

11. All the apples ______ fell down from the tree were eaten up by the pigs.　

A. which　 B. / 　　C. that 　　　 D. they

10. The radio set ______ last week has been out of order.

A.　　 I bought B. I bought it 　

C. which I bought it　 D. what I bought

9. Please pass me the dictionary ______ cover is black.

A. which B. its 　C. whose D. which of

8. The man ____ has gone to Japan.

A.　　 whom I told you 　B. that I told you　

C. whom I told you about him

D. I told you about