Well they arnt going to be silly, they want to know whether you are a good, decent person with the ability and indeed the enthusiasm to be successful and are not simply trying to find out if you can read wikipedia.
That said, reading wikipedia wouldnt be a bad thing. Simple things about aircraft would be a good start, knowing a few terms (the likes of which could be picked up by, say, flight sims (for example, i know what VOR navigation is all about, how it works and things purely through a bit of trial and error in fsx (though probably not enough to pass an exam on the subject and/or do it for real))) wouldnt be a bad thing. If you went in not knowing the feintest thing about the industry youd be wasting your time!