1.That's the boy! Someone gave him my bicycle.
That's the boy who was given my bicycle! (was)
2.These are great stories. People tell them from generation to generation.
These are the great stories which people are told from generation to generation. (told)
3.He's an artist. People buy his paintings for thousands of Euros.
He's the artist whose paintings are sold for thousands of Euros. (sold)
4. That's the old country house. I was born there.
That's the old country house where I was born . (was)
5.It's a type of pen. You can use it under water.
It's a type of pen which can be under water . (be)
6.These are the tourists. Someone has stolen their bags.
These are the tourists whose have been stolen. (been)
7.He's the master criminal. We must stop him!
He's the master criminal who must be stopped . (stopped)