Teacher: little scientists, today we solve the problem that way? (Not before parents into the classroom, the exercise questions) Young: density relationship with the severity. (Teacher: The first pass may be appropriate to remind.) Teacher: So what the same size, the greater the density, the more how to weight (the young: the heavier), the smaller the density of it? (Young: lighter) Teacher: What works in front of you is it? (Young: Rainbow Cup) inside which is the most dense liquid ah? (Young: detergent) which is the minimum density of a liquid inside it? (Young: alcohol) Teacher: You are the best scientists, go and invite parents to come and see our scientific achievements it!