One is in nomadic, hunter-gather societies that often shift camp and that are physically incapable of transporting old people who can't walk when the able-bodied younger people already have to carry their young children and all their physical possessions.
１つは遊牧型の 狩猟採取社会です しばしば住居を移動するため 高齢者が動けなくなると 運ぶことができません 健康な若者は 子供達や所持品を 運ばなければならないのです