It’s a mental problem, a particular technique for checking out oneself, a person’s fellows, and a person’s planet. As a social condition, adolescence persists until the person lays apart the carefree entire world of the child. 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 As an example, "Alice and Bob are the kids of Carl." https://hc6.org/