Đáp án:

1. I went to see a doctor who had helped my father.

2. Mary was wearing the red dress which was made in France.

3. John is one of my closest friends whom I have know him for three years.

4. Ann talked to a man who won a lot of money.

5. He is a architect who designed the new city library.

6. A woman wrote to me who wanted my advice.

7. We stayed at Softel hotel which Mark recommended it to us.

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Form: Mệnh đề quan hệ: 

+ Who: thay thế cho người.

+ Which: thay cho vật và loài vật.

+ Whom: thay cho người.

+ Whose: thay cho người, vật hoặc loài vật.

+ That: Thay cho người, vật hoặc loài vật.