This is known as Pareidolia. Pareidolia is a phenomenon where people assign human qualities to objects that are not related to humans with the most widely known examples being of seeing human faces in objects like the man in the moon or the face on mars. Other well known examples would be seeing shapes in clouds, seeing religious images on food and so forth.
Dewey Decimal System is the library classification system which helps to categorize the books in a correct order - with appropriate location under appropriate subject. The system was introduced by an American librarian and Melvil Dewey and it later used by most of the public libraries in the United States. The correct answer is B.
The correct answer is research
The story is set in New York City's Greenwich Village. This was a popular hangout for artists and other creative types back in the day. Johnsy has a fantasy (fantasy meaning "imagination") that she will die when the last leaf on the ivy vine falls.