1.Who is the man that you said hello to just now?
2.This is the knife with which the doctor did the operation.
3.Those who want to go put up your hands.
4.It is one of the best pictures that have been sold.
5.A plane is a machine that/which can fly.
6.Do you know the young man who has been chosen chairman?
7.This is the only book that was borrwed from the library.
8.The watch that Mother bought for me works very well.
9.The man who came yesterday is our English teacher.
10.He left me the book,which is very useful for me.