Good luck, Panman. You're lucky this subject came up I think, it seems you have one of the concepts here backwards (pun unintentional).
Yes, each blade is an airfoil. However, what would be the top surface if it was a wing is facing front. That is just what is needed to get air moving into the engine. Think of the downwash generated by a wing, or even better that of a helicopter rotor, and you'll be able to see it.
It's the same for a propeller
What's A&C? And hey, as you have an exam coming up, please to drop me a line if I added any confusion.
I thought I was doing good trying to avoid those airport hotels... and look at me now.