Young 1: teacher, my eggs float fri

Young 1: teacher, my eggs float friends. Young 2: I also float friends. Teacher: Congratulations to you, eggs float it, the little scientists, why salt can make the egg float it? Young 1: egg lighter friends. Young 2: I do not know. Teacher: You all played seesaw of it, if you play with seesaw and dad, my father would still be below the Rocker up it? Young 1: Dad will be in the following, because my father is too heavy. Teacher: Oh, because my father heavy weight, it will be in the following, the child will be Qiaoqi to light weight, it's just eggs and salt water, too, oh, eggs are heavier than water, it sank plump, but we after non-stop salt, eggs slowly lighter than salt water, it will float.