When toads take over a new skate park, Sparks' Crew has to help the toads get to their natural habitat. They try out different materials to build a bridge that the toads can use to get home. Curriculum: Different properties of materials make them suited to different purposes. / AJ tries to make a hero clubhouse out of cardboard boxes, but it keeps falling down. Is there a better way to build it so it will stay up? Curriculum: A structure needs to be stable in order to remain upright. Size, shape, and placement can affect the stability of a structure.