The teeth of what animal are so sharp that native americans once used them as knife blades

You think all professors are uncoordinated, but then you see your social psychology professor make a diving catch down the left-field line at an intramural softball game against the arts department team. you also notice that your professor hits lead-off for the team and is able to score from second base on a ground-out. you maintain your original stereotype of professors as uncoordinated by deciding that this one individual is an exception to the rule because he is a “young professor.” this is an example of

About how many crusaders took part in the crusaders

Based on this expert how did banksy counteract this characterization as a "sell out"?