Fill the gaps with the possessive cave of nouns

Here are the answers with the possessive case of nouns: 1. This is Peter's book. 2. Let's go to the theater. (Note: There is no possessive form for 'the theater' given the context of the sentence, if you want to use the possessive form, you might rephrase the sentence to something like: Let's go to John's theater, so the answer will be: Let's go to John's.) 3. The children's room is upstairs. 4. John's sister is twelve years old. 5. Susan and Steve's school is old. 6. The men's shoes are on the second floor. 7. My parents' car was not expensive. 8. Charles' CD player is new. 9. This is the boy's bike. 10. These are the boss's pencils. Please note that for names that end in 's' (like Charles), the possessive form can either add an apostrophe (Charles') or an apostrophe 's' (Charles's), both are acceptable, but some style guides prefer one over the other.