which là đại từ quan hệ thay thế cho danh từ chỉ vật 

    N + which + V + O

    N+ which + S+ V 

who là đại từ quan hệ thay thế cho danh từ chỉ người

that là đại từ quan hệ thay thế cho cả đanh từ chỉ người và vật 

I:Fill in the blanks with WHO, WHICH or THAT:

1. The men ____who ___ lives next-door are English.

2. The dictionary ___which ____ you gave me is very good.

3. Do you know the girls ___who ____ are standing outside the church?

4. The police are looking for the thieve ___who ____ got into my house last night.

5. The chocolate ___which ____ you like comes from the United States.

6. I have lost the necklace ___which ____ my mother gave me on my birthday.

7. A burglar is someone ___that ____ breaks into a house and steals things.

8. Buses ___which ____ go to the airport run every half hour.

9. I can't find the key __which _____ opens this door.

10. I gave you a book __which _____ had many pictures.

11. I don't like the boy ___who ____ Sue is going out with.

12. Did you see the beautiful dress ___that____ she wore yesterday.

13. The man ___who ____ she is going to marry is very rich.

14. This is the bank ___that ____ was robbed yesterday.

15. He wore a mask ___which ____ made him look like Mickey Mouse.