It doesn't contain any punctuation, first of all, and second, it doesn't have a subject. To be a sentence, it must contain a subject. It also must contain one main clause.
-DustinBR
Answer:
To make transitions from one to another narration section in the essay, Diaz uses the rhetorical questions located in paragraph 3, 8 and 10.
B r a m b l e h e a r t.................