Peer groups begin to segregate boys and girls starting in

In humanism or social studies, a peer group is a social and primary gathering of individuals who have comparative interests, age, foundation, or economic wellbeing. The individuals from this gathering are probably going to impact the individual's convictions and conduct. Peer groups contain chains of command and unmistakable examples of conduct.

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c. economic output

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.