In his theory of Cognitive development, Jean Piaget proposed that humans progress through four developmental stages: the sensorimotor, preoperational, concrete operational and formal operational period.
1) oxygen. 2) bone size 3) inner core, outer core 4) 10
That is true! essential body fat is something your body uses. while storage body fat is when you over eat lol
I believe It will collapse on it's self and form a blackhole, most stars do this when they've burnt out all their fuel.