use who,which or where.
3.The children dived into the pool.It has just been cleaned.
4.My mother told my younger sister a bed-time story.It was quite exciting.
5.The teacher caught a boy stealing at school.My older brother knows him.
6.The girl sat next to us in Assembly yesterday.She didn't come to school today.
7.Have you ever been in the old village house in Sai Kung?It is haunted.
8.I want to go to the park.People can let their dogs run and play there.