Воткнуть Who,when,where,which либо whose. Пример:I know a lot of people. They

Воткнуть Who,when,where,which либо whose.
Пример:
I know a lot of people. They believe in a different tomorrow.
I know a lot of people who believe in a different tomorrow.
Решите пожалуйста:
1.This is club. I go dancing there.
2.This is my new CD. I bought it a few days ago.
3.The Backstreet Boys is pop group.They united last year.