Blista, your presentation (I wonder who the audience will be..?) needs to focus, at your level, much more on certification requirements than the complex aerodynamics involved.
This is the key to your question, put, as it is, in the broadest terms, and is the cause behind bookworm's finding above.
Alternatively, start at the NASA website to learn how to stop worrying about lift generation and love your lack of academic success!!!
http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html