Writers should use quotations sparingly. If the whole paper is a series of quotations, how much did the student write?

Quotations are always used for purposes of voice.

Writers generally use short quotations in order to incorporate telling phrases or powerful language into their writing. Short quotations are documented parenthetically, often without drawing attention to the source (a notable exception is when quoting from a literary source for purposes of explication). Long quotations are always introduced by identifying the source in what is called a "running acknowlegement." The following might be reasons of voice for incorporating a long quotation:

Be especially careful regarding that last reason given. Students often offer it as an excuse for quoting an idea or information that should not have been quoted.