Complete the exercise using the correct apostrophe.
1-This is..........book. (Peter)
2-The..............room is upstairs. (children)
3-.......sister is twelve years old. (John)
4-.......and........school is old. (Susan-Steve)
5-...........shoes are on the second floor. (men)
6-My........car was not expensive. (parents)
7-...........CD and player is new. (Charles)
8-This is the..........bike. (boy)
9-These are the........pencils. (boys)