n.自明之理；老生常谈
It is a truism that we never really know the value of something until we lose it. 直到失去才会懂得珍惜，这是条永恒的真理。
He seems to have no unique opinion, and his speech full of truism. 他似乎没有什么独到的见解，他的讲话充满了陈词滥调。
It's a truism but worth repeating: Most middle-class household budgets can be cut. 这是一个老生常谈但值得重复的问题：大多数中产阶级家庭预算都能削减。
n.利他主义；利他
