We're aware of this anyway even in our common experiences or our newspaper stories of the spread of violence from fights or in gang wars or in civil wars or even in genocides.
其实，我们 在日常生活中 或者媒体的报道中都可以了解到 争吵中的暴力会蔓延成 帮派斗争，内战， 甚至蔓延成为种族屠杀。