PDF files are a favorite to hide a meterpreter or other fun payload, people think PDFs are harmless, and most people do not update their adobe as long as it "works", so some still have 7.0 or earlier on their machines. People are taught that pictures, music, documents are not harmful, only programs that run can be harmful, so it is fairly easy to social engineer someone into opening your malicious PDF
Personally, I have not used Acrobat in years.
If you are ever not sure about a PDF, doc, docx, just upload it to your Google Docs account and read it there
This sounds like a persuasive piece, although I have not read it. I agree with the comment about not using the word "prove" unless it is law. Theories are not proven, yet. But since it is a non-technical writing piece and your teacher suggested stronger language, like "prove", it sounds like he wants you to convince the reader of your thesis. If it is not too long, I would like to read your piece