Explain the purpose of the apostrophe in each word, and explain what the apostrophe is probably replacing. If there is more than one possibility, try to get all possibilities and explain each.   1. It's   2. Sue's   3. D'Giorno   4. We'll   5. '70s   6. Bill's   7. 'til   8. They're   9. Aren't   10. O'Reilly