Complete the sentences with who, which or where.

0 A doctor is a person who helps sick people get better.
1 A library is a building ________ you can find a lot of books.
2 A gardener is someone ________ knows a lot about plants.
3 Google is a website ________ helps you find information.
4 A cassette player is an old gadget ________ people used to play and record music.
5 Pierre Omidyar is the man ________ started eBay website.