what's an example of an appostion in the book Miracle Worker?
Study these sites carefully. They will help you identify appositives in the book.
http://grammar.about.com/od/ab/g/appositionterm.htm
http://www.writingcentre.uottawa.ca/hypergrammar/apposit.html
http://www.grammar-monster.com/glossary/appositive_apposition.htm