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4. The man whom I have never met gave me a lift this moring.
5. Scientists are working with stem cells which will revolutionize medicine.
6. Most of the books which I read as a child are still popular today.
7. We won't forget the day when we went to Justin Bieber's concert.
8. The book which Mr.Henry gave to me is about Gagarin's flight to the space.
9. I want to introduce you to Mrs.Black whose husband is a software engineer at Google, Inc.
10. The Nation Air and Space Museum which we visited last year has been renovated.