III. Use correct pronoun (who, that, which, whose…) filling in the gaps.

1. I thought _____________________ that boy is your brother.

2. _________________ book is this?

3. Do you know __________________ I am?

4. Ask him __________________ platform the Boston train leaves from.

5. To ________________ will I address the letter?

6. Tell him ___________________ he must take with him for the picnic.

7. The family ___________________ we stayed with were kind.

8. I don’t know _______________ cat it is.

9. Mary, ____________________ we were talking about, has just come in.

10. We couldn’t imagine __________________ flat it is.

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