The teddy bear that Lois is sleeping with is the same that Clark won for her in The Green, Green Glow of Home (1993).
During the classroom briefing, one child suggests that Superman should have a signal that they could shine in the sky to let him know he is needed, which another child dismisses as stupid! This is of course how Batman is called when he is needed, The Batsignal. Both Batman and Superman are characters of DC Comics.