1/ This is the house in which we often stay in summer.

2/ I'll show you the second hand bookshop in which you can find valuable books.

3/ I have not decided the day when I'll go to London on.

4/ He was born on the day when his father was away on.

5/ The book, which we can look up telephone numbers in, is a telephone directory.

6/ This is a rare opportunity which you should take advantage of to get a better job.

7/ The boy, whom you made fun of, is my cousin.

8/ This matter, which you should pay attention to, is of great importance.

9/ The man, who I respect most, is my father.

10/ The man, whose opinion is respected most, is my father. 

1.This is the house where we often stay in summer.

2.I'll show you the second-hand bookshop where you can find valuable books

3.I haven't decided the day when i'll go to london

4.He was born on the day when his father was away

5. The book, which we can look up telephone numbers in, is a telephone directory.

6. This is a rare opportunity which you should take advantage of to get a better job.

7. The boy, whom you made fun of, is my cousin.

8. This matter, which you should pay attention to, is of great importance.

9. The man, who I respect most, is my father.

10. The man, whose opinion is respected most, is my father.