To him this was not useless, because it didn't serve the state.

这对彼得大帝来说无所功用,因为这对俄国没有任何贡献

耶鲁公开课 - 欧洲文明课程节选

In addition Aristotle tells us such a person will possess beautiful but useless things suggesting the possession not only of wealth but of a kind of cultivated aesthetic sense.

此外，亚里士多德告诉我们,这类的人还将会拥有一些美丽,但无用的东西,不只拥有财富,还有一种经教化的美感。

耶鲁公开课 - 政治哲学导论课程节选

It's not a cyclical and useless definition.

这不是一个循环式的,没有意义的定义

耶鲁公开课 - 基础物理课程节选

Well, simply with the * notation at least on the way in when you declare the function called swap, you simply say this is not going to take an int and another int because that's useless.

好的，简单说，当你声明一个函数调用swap函数时,使用*符号，你可以简单说，这不能使用一个int数和另外一个int数,因为那是无效的。

哈佛公开课 - 计算机科学课程节选