答案:In my opinion, all the three characters are complex. The following are my descriptions about them.
The narrator:
Smart: He is an excellent law student and knows a lot about logic.
Sophisticated: He believes a beautiful and intelligent girlfriend will benefit him in his future career.
Arrogant and self-conceited: He thinks highly of himself but badly of his roommate.
Over-confident: He thinks the girl will surely choose him rather than Rob.
Stupid and simple-minded: He knows nothing about what can happen in real life.
Rob:
Fashionable and cool: He loves fashion and cares a lot about his appearance.
Dishonest: He plays a trick on the narrator to get his leather jacket.
· Clever: He is able to get what he wants without losing anything.
Polly:
Beautiful and nice: She is pretty and easy to be with.
Shallow: She chooses Rob simply because he is fashionable.
Smart: She learns quickly and is full of wit when refusing to be the narrator's girlfriend.