Can you explain why the quotation mark was in putted on this sentence: "Notice,"the professor told the class, "Cassius' choice of imagery when he asks, 'Upon what meat doth this our Ceasar feed that he is grown so great?"

You miscopied the last part --

he is grown so great?'"

Study this site carefully for an explanation of quotation marks.

http://grammar.ccc.commnet.edu/grammar/marks/quotation.htm

The quotation marks in the sentence serve different purposes:

1. Outer Quotation Marks: The first and last quotation marks enclose the entire sentence, "Notice, the professor told the class, Cassius' choice of imagery when he asks, 'Upon what meat doth this our Caesar feed that he is grown so great?". These are used to indicate direct speech or a quotation.

2. Inner Quotation Marks: The second pair of quotation marks, within the sentence, "{{Cassius' choice of imagery when he asks, 'Upon what meat doth this our Ceasar feed that he is grown so great?}}", are used to indicate a quote or dialogue within the outer quotation marks. This quote is what Cassius asks in the play, and the professor is referring to it.

So, the reason for the quotation marks in this sentence is to differentiate between the professor's statement to the class and the specific quote from Cassius within that statement.