1/ I don't know the woman. The son of the woman broke my windows yesterday.
=>I don't know the woman whose son broke my window yesterday.
2/ The most intelligent students here are from Japan. We met them at the meeting yesterday.
=>The most intelligent students whom we met at the meeting yesterday. here are from Japan. We met them at the meeting yesterday.
3/ Mr. Brown is the manager of my company. He is only thirty.
=>Mr. Brown, who is only thirty, is the manager of my company.
4/ The opportunity came unexpectedly. She owed to it her success.
=>The opportunity which owed to it her success came unexpectedly
5/ The man gave me good advice. I spoke to him.
=>The man to whom I spoke gave me good advice.
6/ I'll introduce you a girl. Her name is Helen.
=>I'll introduce the girl whose name is Helen.
7/ Peter is the first person. He was interviewed this morning.
=>Peter is the first person to be interviewed this morning.
8/ I recently went back to Paris. I was born in Paris 30 years ago.
=>I recently went back to Paris where I was born 30 years ago.
9/ That man over there is an artist. I don't know his name.
=> That man over there is an artist whose name I don't know.
10/ My school has 30 computers but most of them are second - hand.
=> My school has 30 computers but most of which are second - hand.
11/The car was made in Japan/ I have researched for it since last year.
=>The car for which I have researched since last year was made in Japan.
12/ Opposite our house there is a nice park. There are some beautiful trees and flowers there.
=>Opposite our house there is a nice park which are some beautiful trees and flowers.
13/ The person is sitting at the desk. You should talk to her about your problems.
=>The person to whom you should talk about your problems is sitting at the desk.
14/ Mr. Edwards has gone into the hospital for some tests. His health hasn't been good recently.
=>Mr. Edwards, whose health hasn't been good recently, has gone into the hospital for some tests.
15/ Do you see those letters? Thay came yesterday evening.
=>Do you see those letters which came yesterday evening?
16/ The psychologists have made many important discoveries. They study the nature of sleep.
=>The psychologists have made many important discoveries which study the nature of sleep.
17/ I'll take you to Dalat. You can enjoy fresh air there.
=> I'll take you to Dalat where you can enjoy fresh air.
18/ I don't know the reason. She was sacked for that reason.
=>I don't know the reason for which she was sacked.
19/ You are the only reason. You won the first prize at Physics in my shool.
=>You are the only person to win the first prize at Physics in my shool.