17. The girl whose hair is curly is my elder sister.
18. He tried to explain why he did such a thing.
19. That's the girl who lives next door.
20. That's the man, whose house has burned down.
21. 1066 was the year when William the Conqueror came to England.
22. This is the skate-park where people come to skateboard.
Ответ: whose, why, who, whose, when, where