BROOMFIELD | Stephen Kelly, an anatomy and physiology teacher at Broomfield High School, first noticed AI in his classroom last year. “Students were working on a research project dealing with the immune system. And the projects that I got were really, really good. A little too good,” said Kelly. “And the students could not explain what they were writing.” A PhD-level project on brain-eating amoeba, turned in by one student, was too complex for e…