Answer:
A fellow jumped off of a wall
it was the most terrible of all
he had went to bed
with a pain in his head
So lesson learned, do not jump off a wall
The Socs and greasers choose to have the rumble in a vacant lot in greaser territory, because the lots is a less conspicuous place where they hoped the cops would not break up the fight.
The main one is the need to be in a crowed and to fit in. hope this answers your question! another one is "Humans' inherent violence"
