Eve, it's just not fair.
We guys get good grades on things we have to study for generally, but when it comes to assignments it's an entirely different question. For the grades the teacher gives for this is partly based on his own opinion of the student. Ofcourse they would never admit it but it's a fact. There's this one girl in my school who's as dumb as a rock but always gets 10/10 for presentations, and this happens with different teachers, just because she's extremely good-looking.
When we complain, we usually get brushed off, when a good-looking girl complians, the teacher goes red and tells them he 'will take a look at it'.