社会系统是个人与个人之间、群体与群体之间关系的网络。
He has not learned the first lesson of life who does not every day surmount a fear.
"Every mental state is transitional."
Don't be afraid to take risks in your career.
逝者从未远离我们,他们在我们心中,在我们脑海里,永远如此。