Answer: Because when Sir Gawain cut off the nights head, the head and reminded him the pact that Gawain had to seek him in a year and a day at the Green Chapel.
I would say that a "Scientific article describing the negative effect of school uniforms" would be your best bet because the article contains factual information about how wearing school uniforms deteriorates a child's creativity ( and whatever the article said)!
I hope that this helped. : )
